Class 10 Physics Chapter 8 Current Electricity

This quiz on ICSE Class 10 Physics Chapter 8: Current Electricity is designed to assess students’ understanding of key concepts such as electric current, potential difference, resistance, Ohm’s Law, series and parallel circuits, electrical power, and energy. It includes a variety of question formats that test conceptual clarity, numerical problem-solving skills, and real-life application of principles related to electric circuits. The quiz encourages critical thinking and reinforces students' ability to analyze circuit diagrams and calculate quantities using appropriate formulas. Ideal for revision or assessment, this quiz supports a strong foundation in the basics of current electricity as outlined in the ICSE curriculum.

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Category: Internal Resistance of a Cell

1. (A) The terminal voltage of a cell decreases when the current drawn from it increases.
(R) The internal resistance of the cell causes a voltage drop proportional to the current.

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Category: Combination of Resistors

2. What is the equivalent resistance when two resistors of $4 \Omega$ and $4 \Omega$ are connected in parallel?

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Category: Potential Difference (P.D.)

3. Which of the following correctly represents the unit of potential difference?

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Category: Factors Affecting Internal Resistance:

4. What happens to the internal resistance when the temperature of the electrolyte increases?

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Category: Statement of Ohm’s Law:

5. What is the SI unit of electrical resistance?

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Category: Internal Resistance of a Cell

6. A battery with an e.m.f. of $10 \, \text{V}$ and internal resistance $1 \, \Omega$ is connected to a $4 \, \Omega$ resistor. What is the terminal voltage across the battery?

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Category: Commercial Energy Consumption

7. If an electric bulb rated 100 W is used for 5 hours daily, what is the energy consumed in kWh in a week?

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Category: Practical Applications of Electrical Concepts

8. A refrigerator rated 200 W is used for 10 hours each day for 30 days. Calculate the total electrical energy consumed in kilowatt-hours (kWh).

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

9. (A) Doubling the resistance in a circuit while keeping the current constant will quadruple the energy dissipated.

(R) The energy dissipated in a resistor is given by $W = I^2Rt$.

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Category: Resistors in Parallel:

10. Three resistors of $2\Omega$, $4\Omega$, and $4\Omega$ are first connected in series and then in parallel. What is the ratio of their equivalent resistances in series to parallel ($R_s/R_p$)?

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Category: Internal Resistance of a Cell

11. A cell has an e.m.f. of 10 V and a terminal voltage of 8 V when delivering a current of 2 A. What is its internal resistance?

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Category: Resistors in Parallel:

12. A battery supplies a total current of 6 A to three parallel-connected resistors of $1 \Omega$, $2 \Omega$, and $3 \Omega$. What is the current through the $2 \Omega$ resistor?

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Category: Combination of resistors in series

13. Three resistors of $2 \Omega$, $3 \Omega$, and $5 \Omega$ are connected in series. What is the equivalent resistance of the combination?

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Category: Area of Cross-Section

14. If the area of cross-section of a conductor is doubled, what happens to its resistance?

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Category: Combination of Resistors

15. Three resistors of $2 \Omega$, $3 \Omega$, and $5 \Omega$ are connected in series. What is the equivalent resistance of the combination?

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Category: Internal Resistance

16. A battery with e.m.f. 6.0 V and internal resistance 0.8 $\Omega$ is connected to an external resistor of 4 $\Omega$. What is the terminal voltage across the battery?

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Category: Factors Affecting Internal Resistance:

17. Three resistors of $2 \Omega$, $3 \Omega$, and $6 \Omega$ are connected in parallel and then connected in series with a cell of emf 12 V and internal resistance $1 \Omega$. What is the total current in the circuit?

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Category: Statement of Ohm’s Law:

18. A conductor initially obeys Ohm's law with resistance $R$. If its temperature increases such that the resistance becomes $1.5R$, and a new potential difference of $3V$ is applied, what is the resulting current if the initial current at $2V$ was $0.4A$?

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Category: Factors affecting the resistance of a conductor

19. What happens to the resistance of a pure metal when it is heated?

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Category: Practical Applications of Electrical Concepts

20. An electric heater is rated 1500 W - 220 V. What is the resistance of its heating element when it is in use?

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Category: Combination of resistors in series

21. (A) The equivalent resistance of three resistors $2 \Omega$, $4 \Omega$, and $6 \Omega$ connected in series is $12 \Omega$.
(R) In a series combination, the equivalent resistance is the sum of all individual resistances.

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Category: Internal Resistance

22. A cell with e.m.f. $6 V$ and internal resistance $1 \Omega$ is connected to an external resistor of $5 \Omega$. What is the terminal voltage of the cell?

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Category: Length of the Conductor

23. A material has a specific resistance of $2 \times 10^{-8} \, \Omega \cdot m$. What is its conductivity?

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Category: Length of the Conductor

24. (A) If the length of a conductor is doubled, its resistance also doubles.
(R) The resistance of a conductor is directly proportional to its length, given by $R \propto l$.

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Category: Charge (Q)

25. Convert $5000 \mu C$ to coulombs (C).

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Category: Electrical Power and Energy

26. An electric heater is rated at $1500 W$ when connected to a $220 V$ power supply. What is the resistance of the heating element when it is in use?

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Category: Factors Affecting Resistance

27. Which of the following statements about superconductors is NOT true?

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Category: Commercial Energy Consumption

28. An electric bulb rated 60 W, 220 V is used for 10 hours daily. What is the energy consumed by the bulb in 15 days in kilowatt-hour (kWh)?

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Category: Length of the Conductor

29. If the length of a conductor is doubled, what happens to its resistance?

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Category: Electrical Energy and Power Consumption

30. (A) A 100 W - 220 V bulb will consume the same amount of electrical energy in 10 hours as a 200 W - 110 V bulb consumes in 5 hours.
(R) The energy consumed by an appliance is given by $E = P \times t$, where $P$ is power and $t$ is time, irrespective of the voltage rating.

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Category: Combination of resistors in parallel

31. A battery supplies 6 A current to a parallel combination of 3 Ω and 6 Ω resistors. What is the current through the 3 Ω resistor?

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Category: Practical Applications of Electrical Concepts

32. (A) An electric heater converts electrical energy into heat energy.
(R) The heating element of an electric heater has high resistance, which causes it to heat up when current passes through it.

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

33. An electric heater rated 2000 W-220 V is operated at its rated voltage for 2 hours. How much electrical energy does it consume?

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Category: TERMINAL VOLTAGE OF A CELL

34. (A) The terminal voltage of a cell is always equal to its emf when no current is drawn from the cell.
(R) When no current is drawn, the voltage drop inside the cell is zero, making the terminal voltage equal to the emf.

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Category: Combination of resistors in series

35. Two resistors $R_1 = 5 \Omega$ and $R_2 = 10 \Omega$ are connected in series to a voltage source. If the power dissipated in $R_1$ is $20 W$, what is the total power dissipated in the circuit?
$P = I^2 R$

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Category: Resistors in Parallel:

36. In a circuit, two resistors $R_1 = 6\,\Omega$ and $R_2 = 3\,\Omega$ are connected in parallel. If the total current drawn from the battery is $9\,A$, what is the current through $R_2$?

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Category: Current (I)

37. Convert $500 mA$ to amperes.

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Category: Combination of Resistors

38. Three resistors of $6 \Omega$, $3 \Omega$, and $2 \Omega$ are connected in parallel, and this combination is connected in series with a $4 \Omega$ resistor. What is the equivalent resistance of the entire circuit?

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Category: Current (I)

39. What is the SI unit of electric current?

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Category: Combination of resistors in series

40. Three resistors of resistances $2 \Omega$, $4 \Omega$, and $6 \Omega$ are connected in series. What is the equivalent resistance of the combination?

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Category: Statement of Ohm’s Law:

41. Which of the following materials is an example of an ohmic resistor?

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Category: Commercial Energy Consumption

42. (A) A household uses a 2000 W air conditioner for 6 hours daily and a 100 W LED bulb for 10 hours daily. If the cost of electricity is \$0.15 per kWh, the total monthly electricity bill will be \$63.
(R) The total energy consumed by the appliances in a month can be calculated using the formula: $\text{Total Energy (kWh)} = \sum_{i=1}^{n} \left( \frac{P_i (\text{W}) \times t_i (\text{h})}{1000} \right)$

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Category: ELECTRICAL ENERGY

43. A refrigerator has a power rating of $250 W$. If it runs for 8 hours per day, what is the energy consumed in one month (30 days) in kilowatt-hours (kWh)?

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Category: Combination of resistors in parallel

44. (A) In a parallel combination of resistors, the equivalent resistance is always less than the smallest individual resistor.
(R) The reciprocal of the equivalent resistance in a parallel combination is equal to the sum of the reciprocals of the individual resistances.

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Category: CHOICE OF MATERIAL OF A WIRE

45. (A) Copper is commonly used for electrical connections and power transmission wires.
(R) Copper has very low specific resistance, which minimizes energy loss due to heating.

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

46. If a potential difference of $6\,V$ is applied across a resistor and the current flowing is $2\,A$, what is the resistance of the resistor?

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Category: Area of Cross-Section

47. A cylindrical pipe of radius $R$ has a rectangular hole of width $2a$ and height $2b$ cut through it along its entire length. The hole is centered such that the distance between the center of the hole and the axis of the cylinder is $d$. What is the maximum possible cross-sectional area of the pipe excluding the hole?

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Category: Current (I)

48. In a circuit, the charge flowing through a resistor varies with time as $Q(t) = 4t^2 + 2t \, \text{C}$, where $t$ is in seconds. What is the current at $t = 3 \, \text{s}$?

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Category: Electrical Energy and Power Consumption

49. An electric bulb rated 60 W is used for 5 hours daily. What is the energy consumed by the bulb in 30 days, in kilowatt-hour (kWh)?

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Category: Potential Difference (P.D.)

50. Which unit represents potential difference?

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Category: Ohm’s Law

51. For an ohmic conductor, what does the slope of the current ($I$) versus voltage ($V$) graph represent?

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Category: TERMINAL VOLTAGE OF A CELL

52. If the work done in carrying a test charge $q$ through the electrolyte inside a cell is $w$, the voltage drop $v$ across the cell is given by:

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Category: Factors Affecting Resistance

53. Two wires A and B of the same material have lengths in the ratio 2:1 and diameters in the ratio 1:2. What is the ratio of their resistances ($R_A : R_B$)?

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Category: Electrical Energy and Power Consumption

54. (A) The energy consumed by a 100 W bulb glowing for 10 hours is 1 kWh.
(R) The commercial unit of electrical energy is kilowatt-hour (kWh), where $1 kWh = 3.6 \times 10^6 J$.

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

55. (A) The current in a conductor is directly proportional to the number of free electrons passing through it per unit time.
(R) Current is defined as the rate of flow of charge, and free electrons are the charge carriers in conductors.

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Category: Internal Resistance

56. A cell of e.m.f. 3.6 V and internal resistance 1.2 $\Omega$ is connected to a resistor of 2.4 $\Omega$. Calculate the current flowing through the circuit.

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Category: TERMINAL VOLTAGE OF A CELL

57. What causes a voltage drop $(v)$ inside a cell when current is drawn from it?

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Category: Electrical Energy and Power Consumption

58. What is the electrical energy consumed by a 100 W bulb if it is used for 5 hours?

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Category: Electrical Energy and Power Consumption

59. If an electric iron rated at 700 W is used for 2 hours daily for 30 days, what is the total cost of electricity at Rs.5 per kWh?

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Category: Factors affecting the resistance of a conductor

60. Two wires A and B are made of the same material. Wire A has length $2l$ and diameter $d$, while wire B has length $l$ and diameter $2d$. How does the resistance of wire A compare to that of wire B?

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Category: Electrical Power and Energy

61. (A) In a household circuit, an appliance rated at 220 V and 1000 W will consume more energy when connected to a 110 V supply for the same duration of time compared to when it is connected to a 220 V supply.
(R) The power consumed by an electrical appliance is directly proportional to the square of the voltage applied across it, given a constant resistance.

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Category: Material of the Conductor

62. (A) Copper is used for electrical connections because its specific resistance is very low.
(R) The resistance of a conductor is inversely proportional to its area of cross section.

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

63. (A) The V-I graph for a metallic conductor at constant temperature is a straight line passing through the origin.
(R) Metallic conductors are ohmic resistors and obey Ohm’s law.

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Category: Combination of resistors in series

64. (A) If three resistors of resistances $R_1$, $R_2$, and $R_3$ are connected in series to a battery, the potential difference across $R_2$ will always be greater than the potential difference across $R_1$ if $R_2 > R_1$.
(R) In a series combination of resistors, the potential difference across each resistor is directly proportional to its resistance.

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Category: ELECTRICAL ENERGY

65. (A) A 100 W - 220 V bulb when connected to a 110 V supply consumes 25 W of power.
(R) The power consumed by an electrical appliance is proportional to the square of the voltage applied across it.

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Category: Length of the Conductor

66. A wire has a resistance of $4 \, \Omega$ at length $1 \, \text{m}$. What will be its resistance if the length is increased to $3 \, \text{m}$?

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Category: Internal Resistance of a Cell

67. (A) The terminal voltage of a cell decreases when current is drawn from it.
(R) Internal resistance causes a voltage drop equal to $Ir$ when current flows through the cell.

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

68. A resistor of 50 Ω is connected to a 20V battery for 5 minutes. Calculate the electrical energy consumed by the resistor.

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Category: Unit of Resistance

69. What is the SI unit of resistance?

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Category: Combination of Resistors

70. A circuit has a 5 Ω resistor in series with a parallel combination of two resistors, each 10 Ω. What is the total equivalent resistance?

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Category: Current (I)

71. Calculate the current if a charge of $10 \text{ C}$ flows through a conductor in $5 \text{ s}$.

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Category: Ohm’s Law

72. Which of the following devices is an example of a non-ohmic resistor?

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Category: Material of the Conductor

73. Which of the following statements is true regarding superconductors?

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Category: Resistors in Parallel:

74. (A) The equivalent resistance of three resistors $R_1 = 2\Omega$, $R_2 = 4\Omega$, and $R_3 = 6\Omega$ connected in parallel is less than $2\Omega$.
(R) In a parallel combination, the reciprocal of the equivalent resistance is equal to the sum of the reciprocals of individual resistances.

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Category: Ohm’s Law

75. What is the SI unit of resistance?

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Category: TERMINAL VOLTAGE OF A CELL

76. When a cell delivers a current of 2 A, its terminal voltage is 9 V. If the current increases to 5 A, and the internal resistance of the cell is 0.5 $\Omega$, what will be the new terminal voltage? Assume the EMF remains constant.

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Category: Potential Difference (P.D.)

77. (A) The terminal voltage of a cell is always equal to its e.m.f.
(R) The voltage drop inside the cell is zero when current is drawn from it.

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Category: Practical Applications of Electrical Concepts

78. (A) The resistance of a 100 W, 220 V electric bulb when glowing is $484 \Omega$.

(R) The resistance of the filament increases with temperature, and the power rating formula $R = \frac{V^2}{P}$ gives the resistance at operating temperature.

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Category: Electrical Power and Energy

79. A bulb is rated $100\, W - 220\, V$. What is its resistance when glowing?

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Category: Internal Resistance of a Cell

80. (A) The terminal voltage of a cell increases when the current drawn from it decreases.
(R) The internal resistance of a cell causes a voltage drop proportional to the current drawn.

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Category: Potential Difference (P.D.)

81. (A) The terminal voltage of a cell is always less than its e.m.f. when current is drawn from it.
(R) Some energy is spent in overcoming the internal resistance of the cell, resulting in a voltage drop inside the cell.

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Category: Combination of Resistors

82. Three resistors of resistances 4 Ω, 6 Ω, and 8 Ω are connected in series. What is the equivalent resistance of the combination?

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Category: Practical Applications of Electrical Concepts

83. An electric heater is rated '1000 W, 220 V'. What is the safe current that can flow through it without causing damage?

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Category: ELECTRICAL ENERGY

84. How many joules are there in 1 kilowatt-hour (kWh)?

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Category: Charge (Q)

85. A body has a charge of $+3.2 \times 10^{-19} C$. How many electrons are in deficit to produce this charge?

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Category: CHOICE OF MATERIAL OF A WIRE

86. (A) Copper is preferred over silver for electrical connections despite silver having lower specific resistance because it provides better mechanical strength.
(R) The choice of material for a wire depends on multiple factors including cost, availability, and resistivity.

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Category: Electrical Power and Energy

87. How much energy in joules is equal to 1 kilowatt-hour (kWh)?

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Category: Ohm’s Law

88. A conductor has a resistance of $10 \Omega$ at 20°C. If the temperature increases to 40°C, and the resistance changes to $12 \Omega$, what is the conductance of the conductor at 40°C?

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Category: Length of the Conductor

89. A wire of resistance $R$ is stretched such that its length becomes three times its original length while maintaining constant volume. What is the new resistance of the wire?

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Category: Combination of Resistors

90. Four resistors of $2 \Omega$, $4 \Omega$, $8 \Omega$, and $16 \Omega$ are connected in parallel. What is the current through the $4 \Omega$ resistor if the total current supplied is $15 A$?

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

91. How many joules are there in 1 kilowatt-hour (kWh)?

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Category: ELECTRICAL ENERGY

92. A resistor of $10 \Omega$ is connected across a battery of $20 V$. How much electrical energy is consumed in 5 minutes?

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Category: Practical Applications of Electrical Concepts

93. A 100 W electric bulb is connected to a 220 V supply. How much electrical energy is converted into light and heat energy in 5 minutes?

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Category: Material of the Conductor

94. A wire of length 2 m and cross-sectional area 1 $\text{mm}^2$ has a resistance of 10 $\Omega$. What is the specific resistance of the material of the wire?

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Category: Resistors in Parallel:

95. Three resistors of values $2 \Omega$, $4 \Omega$, and $8 \Omega$ are connected in parallel. What is the equivalent resistance of the combination?

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Category: Factors Affecting Internal Resistance:

96. Which of the following factors does NOT decrease the internal resistance of a cell?

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Category: Charge (Q)

97. Two identical spheres with charges $+4 \, \mu C$ and $-12 \, \mu C$ are brought into contact and then separated. What is the final charge on each sphere?

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Category: Charge (Q)

98. Two charges, $+Q$ and $-Q$, are placed near each other. What will be the nature of the force between them?

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Category: Electrical Power and Energy

99. What is the expression for electrical energy when current $I$ flows through a conductor of resistance $R$ for time $t$ with potential difference $V$?

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Category: Combination of resistors in series

100. A circuit consists of three resistors $3 \Omega$, $5 \Omega$, and $7 \Omega$ in series connected to a battery. If the current through the circuit is $2 A$, what is the potential difference across the $5 \Omega$ resistor?

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Category: Internal Resistance

101. What is the unit of internal resistance of a cell?

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Category: Material of the Conductor

102. (A) Superconductors are used for power transmission lines to minimize energy loss due to heating.
(R) Superconductors exhibit zero resistance at very low temperatures.

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Category: Material of the Conductor

103. At what temperature range do superconductors exhibit zero resistance?

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Category: Length of the Conductor

104. Which of the following statements about specific resistance is true?

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Category: CHOICE OF MATERIAL OF A WIRE

105. Why is a lead-tin alloy commonly used as a fuse wire?

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Category: Practical Applications of Electrical Concepts

106. What energy transformation occurs in an electric heater?

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

107. What is the charge on a body if it has an excess of $3 \times 10^{18}$ electrons?

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

108. (A) A 100 W bulb consumes 360 kJ of energy in one hour.

(R) The commercial unit of electrical energy, kilowatt-hour, is equivalent to 3.6 MJ.

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

109. If a current of 0.5 A flows through a resistor for 10 seconds, and the resistance is 4 $\Omega$, how much charge passes through the resistor during this time?

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Category: Charge (Q)

110. (A) A body with a charge of $+3.2 \times 10^{-19} \, C$ must have lost two electrons.
(R) The charge on an electron is $-1.6 \times 10^{-19} \, C$, so the loss of two electrons results in a net positive charge of $+3.2 \times 10^{-19} \, C$.

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Category: TERMINAL VOLTAGE OF A CELL

111. (A) The terminal voltage of a cell is always equal to its e.m.f. when the cell is not in use.
(R) When no current is drawn from the cell, there is no voltage drop inside the cell.

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Category: Unit of Resistance

112. (A) The unit of resistance is ohm ($\Omega$).
(R) One ohm is defined as the resistance when a potential difference of 1 volt produces a current of 1 ampere.

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Category: Statement of Ohm’s Law:

113. (A) The $V-I$ graph for a filament bulb is not a straight line passing through the origin.

(R) The resistance of a filament bulb increases with temperature, causing it to be a non-ohmic resistor.

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

114. During the verification of Ohm’s law, the following observations were recorded: Potential difference ($V$) = 6 V, Current ($I$) = 2 A. Later, the current was doubled. If the wire follows Ohm’s law, what will be the new potential difference across it?

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Category: Internal Resistance

115. (A) The terminal voltage of a cell decreases when the current drawn from it increases.
(R) The internal resistance of the cell causes a voltage drop proportional to the current.

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Category: Current (I)

116. (A) The current in a conductor remains constant even if the cross-sectional area of the conductor varies along its length.
(R) Current is a scalar quantity and depends only on the rate of flow of charge, not on the dimensions of the conductor.

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Category: Internal Resistance of a Cell

117. If the terminal voltage of a cell is $4.8 \, \text{V}$ when it delivers a current of $0.4 \, \text{A}$ and its internal resistance is $2 \, \Omega$, what is its e.m.f.?

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Category: Unit of Resistance

118. A resistance wire has a resistance of 5000 $\Omega$. What is its resistance in kilo-ohm?

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

119. A 100 W bulb is connected to a 220 V supply. What is the resistance of its filament when glowing?

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Category: Internal Resistance of a Cell

120. If a cell has an e.m.f. $\epsilon$ and internal resistance $r$, what is its terminal voltage $V$ when a current $I$ flows through it?

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Category: Commercial Energy Consumption

121. A refrigerator consumes 150 W and runs continuously for 24 hours. What is the energy consumed in joules if 1 kWh = $3.6 \times 10^6$ J?

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Category: Practical Applications of Electrical Concepts

122. A device is rated 1000 W - 220 V. What is the safe current that can flow through it?

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

123. In an experiment to verify Ohm’s law, what is the relationship between voltage (\$V\$) and current (\$I\$) for an ohmic conductor?

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Category: Length of the Conductor

124. (A) When a conductor is stretched to twice its original length while keeping its volume constant, its resistance becomes four times the original resistance.
(R) The resistance of a conductor is directly proportional to the square of its length when the volume remains constant.

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Category: Factors Affecting Resistance

125. If the length of a wire is doubled while its cross-sectional area remains the same, what happens to its resistance?

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Category: Potential Difference (P.D.)

126. Two points $A$ and $B$ are located in an electric field such that $50 \text{ J}$ of work is done to move $5 \text{ C}$ charge from $A$ to $B$. If the potential at point $A$ is $10 \text{ V}$, what is the potential at point $B$?

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Category: Factors Affecting Internal Resistance:

127. How does increasing the ionic nature of the electrolyte affect the internal resistance of a cell?

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Category: TERMINAL VOLTAGE OF A CELL

128. The terminal voltage of a cell is equal to its e.m.f. when:

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Category: Electrical Power and Energy

129. An electric heater consumes 1.2 kWh of energy in 30 minutes. What is the power rating of the heater?

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Category: Combination of Resistors

130. A $6 \Omega$ resistor is connected in series with a parallel combination of two $6 \Omega$ resistors. What is the total equivalent resistance?

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Category: Combination of resistors in parallel

131. What is the equivalent resistance of two resistors $R_1 = 2 \Omega$ and $R_2 = 4 \Omega$ connected in parallel?

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Category: Combination of Resistors

132. Two resistors of $4 \Omega$ and $12 \Omega$ are connected in parallel. What is the equivalent resistance of the combination?

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Category: Internal Resistance of a Cell

133. A cell of e.m.f. $2.5 \, \text{V}$ and internal resistance $1.5 \, \Omega$ is connected to an external resistor of $3.5 \, \Omega$. What is the terminal voltage across the cell when current is drawn?

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Category: Commercial Energy Consumption

134. An electric heater rated 2000 W is used for 2 hours daily, and a 40 W bulb is used for 8 hours daily. If the cost of electricity is Rs. 5 per kWh, what is the total cost for 15 days?

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

135. If a current of $2.5 \, mA$ flows through a conductor for 8 seconds, how much charge passes through it?

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Category: Electrical Energy and Power Consumption

136. (A) The electrical energy consumed by a 100 W bulb glowing for 5 hours is 0.5 kWh.
(R) Electrical energy in kWh is calculated using the formula $\text{Energy (kWh)} = \frac{\text{Power (W)} \times \text{Time (h)}}{1000}$.

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Category: Charge (Q)

137. (A) A body with a charge of $+3.2 \times 10^{-19} C$ has lost two electrons.
(R) The charge on an electron is $-1.6 \times 10^{-19} C$.

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

138. (A) The potential difference across a resistor increases if its resistance is doubled while keeping the current constant.
(R) According to Ohm's law ($V = IR$), potential difference ($V$) is directly proportional to the resistance ($R$) when current ($I$) is constant.

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Category: Area of Cross-Section

139. A wire is bent into the shape of the curve $y = x^2$ from $x = -1$ to $x = 1$. If the cross-sectional area of the wire varies as $A(x) = 2 + e^{-x^2}$, what is the total volume of the wire?

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Category: Combination of Resistors

140. A circuit consists of two resistors $R_1 = 5 \Omega$ and $R_2 = 10 \Omega$ in series, and this combination is connected in parallel with another resistor $R_3 = 15 \Omega$. What is the equivalent resistance of the entire circuit?

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Category: Practical Applications of Electrical Concepts

141. If an electric bulb is rated 60 W - 220 V, what is the resistance of its filament when glowing?

142 / 360

Category: Internal Resistance

142. (A) For a cell with non-zero internal resistance, the terminal voltage equals its emf when no current is drawn from the cell.
(R) The voltage drop across the internal resistance $v = I r$ becomes zero when $I = 0$.

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Category: Internal Resistance

143. (A) The terminal voltage of a cell decreases when current is drawn from it.
(R) The internal resistance of the cell causes a voltage drop equal to $Ir$.

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Category: Unit of Resistance

144. Convert 2 kilo-ohms to ohms.

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Category: Electrical Energy and Power Consumption

145. Three appliances—a fan (60 W), a TV (120 W), and a tube light (40 W)—are used for 5 hours daily. What is the total energy consumed in kWh in one week (7 days)?

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Category: Combination of resistors in series

146. Three resistors $R_1 = 4 \Omega$, $R_2 = 6 \Omega$, and $R_3$ are connected in series across a battery such that the total potential difference across the combination is $24 V$. If the potential difference across $R_3$ is $12 V$, what is the value of $R_3$?
$V = V_1 + V_2 + V_3$

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Category: Internal Resistance of a Cell

147. A cell of e.m.f. $\epsilon$ and internal resistance $r$ is connected to a variable resistor. When the resistor is set to 10 $\Omega$, the current is 1 A, and when it is set to 20 $\Omega$, the current drops to 0.6 A. What is the internal resistance $r$ of the cell?

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Category: TERMINAL VOLTAGE OF A CELL

148. When a cell is in use, how does its terminal voltage $(V)$ compare to its e.m.f. $(E)$?

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Category: Factors affecting the resistance of a conductor

149. A tungsten filament bulb operates at 3000 K with a resistance of $1200 \Omega$. At room temperature (300 K), the resistance drops to $100 \Omega$. If the filament's length is increased by 50\% and its radius is reduced by 20\% at 3000 K, what will be the new operating resistance?

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Category: Current (I)

150. (A) If $1 \text{ C}$ of charge flows through a conductor in $1 \text{ s}$, the current is $1 \text{ A}$.
(R) Current is defined as the rate of flow of charge, given by $I = \frac{Q}{t}$.

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Category: Charge (Q)

151. (A) A body with an excess of electrons will carry a negative charge.
(R) Electrons carry a negative charge, and any excess or deficit of these particles determines the overall charge on the body.

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Category: Statement of Ohm’s Law:

152. Which of the following statements is true for an ohmic conductor under constant temperature?

153 / 360

Category: CHOICE OF MATERIAL OF A WIRE

153. Why is a lead-tin alloy commonly used for fuse wires?

154 / 360

Category: Ohm’s Law

154. (A) The resistance of a conductor decreases as its temperature increases.
(R) For ohmic resistors, the $V-I$ curve is linear and passes through the origin.

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Category: TERMINAL VOLTAGE OF A CELL

155. What is the terminal voltage $(V)$ of a cell defined as?

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Category: ELECTRICAL ENERGY

156. A bulb is rated 60 W - 120 V. What is the resistance of its filament when it is glowing?

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Category: Factors Affecting Resistance

157. (A) The resistance of a copper wire increases when its length is doubled.
(R) Resistance is directly proportional to the length of the conductor.

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

158. In an experiment to verify Ohm’s law, a student plots the potential difference ($V$) against current ($I$) for a metallic conductor. The slope of the resulting straight-line graph is found to be 5 $\Omega$. If the temperature of the conductor increases during the experiment due to Joule heating, what will be the effect on the slope of the $V-I$ graph?

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Category: Resistors in Parallel:

159. (A) The equivalent resistance of a parallel combination of resistors is always less than the smallest individual resistance in the combination.
(R) In a parallel combination, the total current divides among the resistors inversely proportional to their resistances.

160 / 360

Category: Factors affecting the resistance of a conductor

160. Which material has the highest specific resistance ($\rho$) among the following?

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Category: Factors Affecting Internal Resistance:

161. Which of the following changes will decrease the internal resistance of a cell?

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Category: Factors Affecting Resistance

162. Which of the following materials has the lowest resistivity at room temperature?

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Category: TERMINAL VOLTAGE OF A CELL

163. The work done in moving a charge of 4 C through the external circuit connected to a cell is 20 J. If the voltage drop inside the cell for the same charge is 3 J, what is the EMF of the cell?

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Category: Potential Difference (P.D.)

164. A cell has an e.m.f. of $6 \text{ V}$ and an internal resistance causing a voltage drop of $1 \text{ V}$. If the terminal voltage is measured to be $4 \text{ V}$, what is the work done in moving $2 \text{ C}$ charge through the external circuit?

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Category: Length of the Conductor

165. Which of the following materials is commonly used as a superconductor at very low temperatures?

166 / 360

Category: Combination of resistors in parallel

166. (A) In a parallel combination of resistors, the potential difference across each resistor is the same.
(R) All resistors in parallel are connected between the same two points.

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Category: Combination of Resistors

167. Three resistors of resistances $2\,\Omega$, $4\,\Omega$, and $6\,\Omega$ are connected as follows: the $2\,\Omega$ and $4\,\Omega$ resistors are in parallel, and this combination is connected in series with the $6\,\Omega$ resistor. What is the equivalent resistance of the entire circuit?

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

168. (A) The electrical energy supplied by a source is given by $W = VIt$.
(R) This is because the work done to move charge $Q$ through a potential difference $V$ is $W = QV$ and $Q = It$.

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Category: Factors affecting the resistance of a conductor

169. (A) The resistivity of a semiconductor decreases with an increase in temperature.
(R) At higher temperatures, the number of charge carriers in a semiconductor increases significantly.

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

170. (A) The slope of the V-I graph for an ohmic resistor gives its resistance.
(R) For an ohmic resistor, the V-I graph is a straight line passing through the origin.

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Category: ELECTRICAL ENERGY

171. (A) An electric bulb rated 100 W - 220 V consumes more electrical energy than a bulb rated 60 W - 220 V when both are used for the same duration.
(R) The power rating of an electrical appliance indicates the rate at which it converts electrical energy into other forms of energy.

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Category: Factors Affecting Resistance

172. A wire of length $l$ and cross-sectional area $A$ has a resistance $R$. If the wire is stretched such that its length becomes $3l$, what will be its new resistance? (Assume volume remains constant.)

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Category: Combination of resistors in series

173. Four resistors of equal resistance $2 \Omega$ are connected in series. If the total voltage across the combination is $24 V$, what is the voltage drop across each resistor?

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Category: Internal Resistance

174. A battery has an open-circuit voltage of $10\, \text{V}$. When connected to a $15\, \Omega$ resistor, its terminal voltage drops to $9\, \text{V}$. What is its internal resistance?

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Category: Internal Resistance of a Cell

175. A battery with an e.m.f. of 12 V and internal resistance $r$ is connected to a resistor of 4 $\Omega$. If the terminal voltage across the battery is 10 V, what is the value of $r$?

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Category: CHOICE OF MATERIAL OF A WIRE

176. What type of material is used for making standard resistors due to their high resistance and minimal change in resistance with temperature?

177 / 360

Category: Combination of resistors in parallel

177. Two identical resistors each of 10 Ω are first connected in series and then in parallel. The ratio of their equivalent resistances (series to parallel) is:

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Category: Electrical Power and Energy

178. (A) The electrical energy consumed by an appliance is given by $W = VIt$.
(R) The potential difference ($V$) across a conductor is defined as the work done to move a unit charge through it.

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Category: CHOICE OF MATERIAL OF A WIRE

179. A copper wire of length 2 m and cross-sectional area $1 \times 10^{-6} \, m^2$ is stretched to double its original length while maintaining its volume. What will be the new resistance of the wire? (Given: $\rho_{Cu} = 1.73 \times 10^{-8} \, \Omega \, m$)

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Category: Combination of Resistors

180. A combination consists of two resistors $R_1 = 4\,\Omega$ and $R_2 = 6\,\Omega$ connected in parallel, which is then connected in series with a resistor $R_3 = 5\,\Omega$. If a voltage of 10 V is applied across the entire circuit, what is the current through $R_3$?

181 / 360

Category: Ohm’s Law

181. According to Ohm's law, if the potential difference across a conductor is 10 V and the current flowing through it is 2 A, what is the resistance of the conductor?

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Category: Area of Cross-Section

182. (A) Doubling the area of cross-section of a conductor reduces its resistance to half of the original value.
(R) Resistance is inversely proportional to the area of cross-section of the conductor.

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

183. A charge of 5 C is moved between two points in an electric field, and the work done is 25 J. What is the potential difference between the two points?

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Category: Commercial Energy Consumption

184. An electric bulb is rated 100 W at 220 V. If the voltage drops to 200 V, what is the approximate power consumed by the bulb? Assume the resistance remains constant.

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

185. What is the expression for electrical energy $W$ supplied by a source when current $I$ flows for time $t$ under potential difference $V$?

186 / 360

Category: Practical Applications of Electrical Concepts

186. (A) An electric bulb rated '100 W - 220 V' will consume more electrical energy when operated at 110 V compared to its rated voltage.
(R) The power consumed by an electrical appliance is directly proportional to the square of the voltage applied across it.

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Category: Electrical Power and Energy

187. If the potential difference across a resistor is 100 V and the current through it is 2 A, what is the power dissipated by the resistor?

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Category: Charge (Q)

188. How many electrons must be removed from a neutral object to give it a charge of $+32 \, nC$?

189 / 360

Category: Commercial Energy Consumption

189. (A) The commercial unit of electrical energy is kilowatt-hour (kWh).
(R) 1 kWh equals the energy consumed by a 1 kW appliance for 1 hour.

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Category: Combination of Resistors

190. Three resistors of $2\,\Omega$, $3\,\Omega$, and $6\,\Omega$ are connected in parallel. What is their equivalent resistance?

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Category: Statement of Ohm’s Law:

191. (A) A conductor obeys Ohm’s law if its resistance remains constant with varying potential difference.
(R) For a conductor obeying Ohm’s law, the $I$-$V$ graph is a straight line passing through the origin.

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Category: Internal Resistance of a Cell

192. (A) The terminal voltage of a cell decreases when the current drawn from it increases.

(R) The internal resistance of a cell causes a voltage drop proportional to the current flowing through it.

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Category: Factors Affecting Internal Resistance:

193. (A) Increasing the temperature of the electrolyte decreases the internal resistance of a cell.
(R) Higher temperature increases the mobility of ions in the electrolyte, reducing resistance.

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Category: Unit of Resistance

194. Which material exhibits an increase in specific resistance with temperature?

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Category: Electrical Energy and Power Consumption

195. A refrigerator rated 150 W is used for 24 hours daily for a month (30 days). If electricity costs Rs.5 per kWh, what is the total cost of electricity consumed by the refrigerator in the month?

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Category: ELECTRICAL ENERGY

196. An appliance consumes electrical energy at the rate of 500 W for 4 hours every day. How much total energy is consumed in 15 days in kWh?

197 / 360

Category: Factors affecting the resistance of a conductor

197. A copper wire of length $l$, cross-sectional area $a$, and resistance $R$ at temperature $T_1$ is heated to a higher temperature $T_2$. If the wire's length is doubled and its radius is halved, while keeping the material constant, what will be the new resistance at temperature $T_2$ assuming the temperature coefficient of resistance is negligible?

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Category: Unit of Resistance

198. A wire of length 2 m and cross-sectional area $4 \times 10^{-6} \, m^2$ has a resistance of 3 $\Omega$. What is its resistivity?

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Category: TERMINAL VOLTAGE OF A CELL

199. For a cell with e.m.f. $E$, terminal voltage $V$, and internal voltage drop $v$, which equation correctly represents their relationship?

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Category: Combination of Resistors

200. (A) When three identical resistors are first connected in series and then in parallel, the ratio of their equivalent resistances is 9:1.
(R) For n identical resistors each of resistance R, the equivalent resistance in series is nR while in parallel it is R/n.

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Category: Electrical Energy and Power Consumption

201. A geyser is rated '1500 W - 220 V'. What is the resistance of its heating element when it is operating?

202 / 360

Category: Combination of Resistors

202. (A) The equivalent resistance of two resistors $R_1$ and $R_2$ connected in series is greater than the equivalent resistance when they are connected in parallel.
(R) In a series combination, resistances add up directly, whereas in a parallel combination, the reciprocal of resistances add up.

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Category: Current (I)

203. What is the definition of electric current?

204 / 360

Category: Combination of resistors in parallel

204. (A) When three resistors of resistances $R_1$, $R_2$, and $R_3$ are connected in parallel, the equivalent resistance is always less than the smallest individual resistance.
(R) In a parallel combination, the total current divides into branches such that the current through each resistor is inversely proportional to its resistance.

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Category: Internal Resistance

205. A cell has an e.m.f. of $5 V$ and an internal resistance of $0.5 \Omega$. If a current of $2 A$ is drawn from the cell, what is the voltage drop across the internal resistance?

206 / 360

Category: Area of Cross-Section

206. What is the correct formula to calculate the resistance ($R$) of a conductor with specific resistance ($\rho$), length ($l$), and area of cross-section ($A$)?

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Category: Internal Resistance

207. A cell of e.m.f. $6\, \text{V}$ and internal resistance $0.8\, \Omega$ is connected in series with a resistor of $7.2\, \Omega$ and an ammeter of negligible resistance. What will the ammeter read?

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

208. A wire has a resistance of \$10 \Omega\$. If the potential difference across it is \$5 V\$, what is the current flowing through it?

209 / 360

Category: Internal Resistance

209. A battery with an e.m.f. of $12\, \text{V}$ and internal resistance $r$ is connected to a variable resistor $R$. When $R = 4\, \Omega$, the terminal voltage is $9.6\, \text{V}$. What is the value of $r$?

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Category: Commercial Energy Consumption

210. (A) The cost of electricity for a 1 kW appliance used for 5 hours daily at Rs.5 per kWh is Rs.25 per day.
(R) The electrical energy consumed by an appliance can be calculated using the formula $Energy (in kWh) = power (in kW) \times time (in h)$.

211 / 360

Category: CHOICE OF MATERIAL OF A WIRE

211. A wire made of manganin is heated to 100°C from room temperature (25°C). If its specific resistance at 25°C is $44 \times 10^{-8} \, \Omega \, m$, what will be its new specific resistance at 100°C?

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Category: Area of Cross-Section

212. A wire has a resistance of $6 \, \Omega$. If its area of cross-section is doubled while keeping the length constant, what will be the new resistance?

213 / 360

Category: Factors Affecting Internal Resistance:

213. A cell has an e.m.f. of $3.0 \, \text{V}$ and internal resistance $1.5 \, \Omega$. If the terminal voltage is $2.4 \, \text{V}$, what is the current drawn from the cell?

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Category: Unit of Resistance

214. Which of the following represents the correct relationship between conductance and resistance?

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Category: TERMINAL VOLTAGE OF A CELL

215. (A) The terminal voltage of a cell is always equal to its e.m.f.
(R) When no current is drawn from the cell, the terminal voltage equals the e.m.f.

216 / 360

Category: Combination of Resistors

216. Two resistors of resistances 12 Ω and 6 Ω are connected in parallel. What is their equivalent resistance?

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

217. (A) The electrical energy dissipated in a resistor increases when both the current through it and its resistance are doubled.
(R) According to the formula $W = I^2Rt$, if both current ($I$) and resistance ($R$) are doubled, the energy dissipation ($W$) becomes four times its original value.

218 / 360

Category: Ohm’s Law

218. For an ohmic resistor, the slope of the $I-V$ graph is found to be $0.02 \, \text{A/V}$. What is the resistance of this resistor?

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Category: Current (I)

219. (A) If a current of 1 A flows through a conductor for 1 second, the total charge passing through it is 1 C.
(R) Current is defined as the rate of flow of charge, given by $I = \frac{Q}{t}$.

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Category: Internal Resistance of a Cell

220. (A) The terminal voltage of a cell decreases when current is drawn from it.
(R) The internal resistance of the cell causes a voltage drop when current flows through it.

221 / 360

Category: Combination of resistors in parallel

221. Three resistors $R_1 = 3\Omega$, $R_2 = 6\Omega$ and $R_3 = 9\Omega$ are connected in parallel across a battery which delivers a total current of 11A. What is the current through the 6$\Omega$ resistor?

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

222. If an appliance has a power rating of $100~W$ at $220~V$, what is its resistance?

223 / 360

Category: CHOICE OF MATERIAL OF A WIRE

223. Which material is most suitable for making heating elements in appliances like toasters and ovens?

224 / 360

Category: Combination of Resistors

224. (A) In a circuit with three resistors, when two resistors are connected in parallel and this combination is connected in series with the third resistor, the equivalent resistance of the entire circuit will always be greater than the smallest individual resistor.
(R) The equivalent resistance of resistors in parallel is always less than the smallest resistor in the combination.

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Category: Material of the Conductor

225. A copper wire of length 5 m and radius 1 mm has a resistance of 0.05 $\Omega$. What is the specific resistance of copper?

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Category: Internal Resistance

226. A cell has an e.m.f. of 4.5 V and a terminal voltage of 4.0 V when the current drawn is 0.5 A. What is the internal resistance of the cell?

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Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

227. (A) An electrical appliance rated 1 kW - 220 V will consume less energy when operated at 110 V for the same duration compared to 220 V.

(R) The power consumed by an electrical appliance is directly proportional to the square of the voltage applied across it.

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Category: Material of the Conductor

228. (A) Copper is widely used for electrical wiring because it has low specific resistance.
(R) The specific resistance of copper is $1.73 \times 10^{-8} \, \Omega \cdot m$.

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Category: Internal Resistance of a Cell

229. Two identical cells each with emf $2\,V$ and internal resistance $1\,\Omega$ are connected in parallel across an external resistor $R = 1\,\Omega$. What is the current through the external resistor?

230 / 360

Category: Factors Affecting Resistance

230. Which of the following materials is likely to have the highest specific resistance at room temperature?

231 / 360

Category: Resistors in Parallel:

231. In a parallel circuit with three resistors $R_1 = 3\Omega$, $R_2 = 6\Omega$, and $R_3 = 9\Omega$, if the total current supplied is 18A, what is the current through $R_3$?

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Category: Length of the Conductor

232. A wire has a resistance of $R$ ohms. If its length is increased to three times its original length while keeping the volume constant, what will be its new resistance?

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Category: Area of Cross-Section

233. A solid has a base in the shape of an equilateral triangle with side length $a$. The cross-sections perpendicular to the base are semicircles. What is the volume of the solid?

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Category: Combination of resistors in series

234. (A) In a series combination of resistors, the equivalent resistance is always greater than the largest individual resistance.
(R) The equivalent resistance in a series combination is the sum of all individual resistances.

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

235. A student measures the voltage-current characteristics of two different components, A and B. Component A shows a linear $V-I$ relationship passing through the origin, while component B shows a non-linear $V-I$ curve. Which of the following statements correctly identifies the nature of components A and B?

236 / 360

Category: Internal Resistance of a Cell

236. A cell of emf $6\,V$ and unknown internal resistance $r$ is connected to an external resistor $R = 4\,\Omega$. If the power dissipated in the external resistor is $4\,W$, what is the internal resistance of the cell?

237 / 360

Category: Potential Difference (P.D.)

237. What is the electric potential at a point if 30 joules of work is done to bring a charge of 6 coulombs from infinity to that point?

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

238. The work done to move a charge of $5 \, C$ from point A to point B is $25 \, J$. What is the potential difference between points A and B?

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Category: Material of the Conductor

239. Which material is commonly used for electrical transmission wires due to its low specific resistance and cost-effectiveness?

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Category: Commercial Energy Consumption

240. An electric fan has a power rating of 80 W. If it runs for 10 hours a day for 30 days at a cost of Rs.5 per kWh, what is the total cost of electricity?

241 / 360

Category: ELECTRICAL ENERGY

241. An electric bulb converts electrical energy primarily into which of the following forms of energy?

242 / 360

Category: Length of the Conductor

242. What is the correct formula for calculating the resistance of a conductor?

243 / 360

Category: Electrical Energy and Power Consumption

243. An electric bulb is rated 60 W - 220 V. What is the resistance of its filament when it is glowing?

244 / 360

Category: Combination of resistors in series

244. Two resistors $5 \Omega$ and $7 \Omega$ are connected in series. If the total potential difference across the combination is $24 V$, what is the potential difference across the $5 \Omega$ resistor?

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Category: Factors Affecting Internal Resistance:

245. (A) For a cell with e.m.f. $E$, if the terminal voltage $V$ decreases when the current drawn from the cell increases, it implies that the internal resistance $r$ of the cell is significant.
(R) The terminal voltage $V$ is given by $V = E - Ir$, where $I$ is the current drawn and $r$ is the internal resistance.

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Category: Statement of Ohm’s Law:

246. A filament bulb has a non-linear $V-I$ relationship given by $V = kI^2$, where $k = 10\;\Omega/A$. What is the power dissipated when a current of $1A$ flows through it?

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

247. A body has a deficit of $3 \times 10^{12}$ electrons. What is the charge on the body?

248 / 360

Category: ELECTRICAL ENERGY

248. (A) The electrical energy consumed by an appliance is measured in kilowatt-hours (kWh).
(R) Kilowatt-hour is the unit of electrical power.

249 / 360

Category: Internal Resistance of a Cell

249. What is the internal resistance of a cell?

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Category: ELECTRICAL ENERGY

250. An electric heater has a power rating of 2000 W and is used for 3 hours daily. If the cost of electricity is Rs.5 per kWh, what is the monthly cost of using the heater?

251 / 360

Category: Combination of resistors in parallel

251. A 12V battery is connected to two resistors $R_1 = 4\Omega$ and $R_2 = 6\Omega$ in parallel. Calculate the total power dissipated in the circuit.

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Category: CHOICE OF MATERIAL OF A WIRE

252. A heating element for an electric oven must operate at 1000°C without melting and have high resistance to minimize current for a given power output. Which material is most suitable for this purpose?

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Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

253. (A) The charge on a body is quantized because it can only exist as an integer multiple of the elementary charge $e$.
(R) The elementary charge $e$ is the smallest possible charge that can exist independently.

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Category: Area of Cross-Section

254. What is the relationship between conductivity ($\sigma$) and specific resistance ($\rho$)?

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Category: Potential Difference (P.D.)

255. If the e.m.f. of a cell is 12 volts and the voltage drop inside the cell is 2 volts, what is the terminal voltage of the cell?

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Category: Internal Resistance of a Cell

256. When a cell of e.m.f. $6 \, \text{V}$ and internal resistance $0.5 \, \Omega$ delivers a current of $2 \, \text{A}$, how much power is dissipated as heat due to its internal resistance?

257 / 360

Category: Statement of Ohm’s Law:

257. If the potential difference ($V$) across a resistor is 12 V and the current ($I$) flowing through it is 3 A, what is the resistance ($R$) of the resistor?

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Category: Unit of Resistance

258. The conductance of a wire is 0.02 S. What is its resistance?

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Category: Potential Difference (P.D.)

259. If 50 joules of work is done in moving a charge of 10 coulombs from point A to point B, what is the potential difference between points A and B?

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Category: Internal Resistance of a Cell

260. A battery with an e.m.f. of 15 V and internal resistance 2 $\Omega$ is connected to a load resistor $R$. If the power dissipated in the load is maximum, what is the terminal voltage across the battery?

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Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

261. (A) The slope of the V-I graph gives the resistance of the conductor.
(R) For an ohmic resistor, the V-I graph is a straight line passing through the origin.

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Category: Electrical Energy and Power Consumption

262. If an electric oven consumes 180 kWh of energy in a month at a cost of Rs.5 per kWh, what is the total electricity bill for that month?

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Category: Unit of Resistance

263. A conductor has a resistance of 10 $\Omega$ when a current of 2 A flows through it. What is the potential difference across the conductor?

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Category: Charge (Q)

264. If a body has a deficit of $3 \times 10^{18}$ electrons, what is its charge? ($e = -1.6 \times 10^{-19} \, C$)

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Category: Combination of resistors in series

265. Three resistors $4 \Omega$, $6 \Omega$, and $10 \Omega$ are connected in series to a battery. If the current through the $4 \Omega$ resistor is $2 A$, what is the current through the $10 \Omega$ resistor?

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Category: Factors affecting the resistance of a conductor

266. (A) The resistance of a copper wire increases when it is stretched to double its length.
(R) The resistance of a conductor is inversely proportional to its cross-sectional area.

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Category: Current (I)

267. If $3.125 \times 10^{19}$ electrons pass through a conductor in 5 seconds, calculate the current. (Given: Charge of one electron $e = 1.6 \times 10^{-19} C$)

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Category: Area of Cross-Section

268. (A) If a wire of resistance $R$ is stretched such that its length doubles while the volume remains constant, its new resistance will be $4R$.
(R) The resistance $R$ of a wire is directly proportional to its length $l$ and inversely proportional to its area of cross-section $A$.

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Category: Internal Resistance of a Cell

269. What is the internal resistance of a cell?

270 / 360

Category: Resistors in Parallel:

270. If two identical resistors, each with resistance $10\,\Omega$, are connected in parallel, what is their equivalent resistance?

271 / 360

Category: Potential Difference (P.D.)

271. (A) The potential difference between two points is a scalar quantity.
(R) Potential difference is defined as the work done per unit charge, and work is a scalar quantity.

272 / 360

Category: Factors affecting the resistance of a conductor

272. (A) The resistance of a conductor increases with an increase in its temperature.
(R) At higher temperatures, the random motion of electrons increases, leading to more collisions with positive ions.

273 / 360

Category: Commercial Energy Consumption

273. What is the equivalent of 1 kilowatt-hour (kWh) in joules?

274 / 360

Category: Area of Cross-Section

274. Why are power transmission wires made thick in diameter?

275 / 360

Category: Factors Affecting Resistance

275. A conductor has resistance $R_1$ at temperature $T_1$ and $R_2$ at temperature $T_2$ ($T_2 > T_1$). Which of the following correctly describes the relationship between $R_1$ and $R_2$?

276 / 360

Category: Ohm’s Law

276. A conductor has a resistance of $10 \Omega$. If the potential difference across its ends is 20 V, what is the current flowing through it?

277 / 360

Category: Factors Affecting Resistance

277. (A) The resistance of a copper wire increases when its length is doubled.
(R) Resistance is directly proportional to the length of the conductor.

278 / 360

Category: TERMINAL VOLTAGE OF A CELL

278. A cell with an EMF of 12 V has a terminal voltage of 10.8 V when connected to an external circuit. What is the voltage drop inside the cell?

279 / 360

Category: Combination of Resistors

279. (A) The equivalent resistance of two resistors connected in parallel is always less than the smallest resistance in the combination.
(R) In a parallel combination, the total current divides among the resistors inversely proportional to their resistances.

280 / 360

Category: Combination of resistors in parallel

280. Five identical resistors each of resistance $R$ are connected in parallel. The combination is then connected in series with another resistor of value $2R$. If the equivalent resistance of the entire circuit is 3$\Omega$, what is the value of $R$?

281 / 360

Category: Commercial Energy Consumption

281. A household uses two 60 W bulbs for 5 hours, a 1500 W geyser for 30 minutes, and a 750 W mixer for 15 minutes daily. What is the total energy consumed in kWh in a month (30 days)?

282 / 360

Category: ELECTRICAL ENERGY

282. An electric bulb is rated as $60 W - 220 V$. What is the power consumed by the bulb if it operates at $110 V$?

283 / 360

Category: Combination of Resistors

283. What is the equivalent resistance when three resistors of $2 \Omega$, $3 \Omega$, and $5 \Omega$ are connected in series?

284 / 360

Category: Internal Resistance of a Cell

284. A cell of e.m.f. $\epsilon = 12 \, \text{V}$ has a terminal voltage of $9 \, \text{V}$ when connected to an external resistor. If the current drawn is $1.5 \, \text{A}$, what is the internal resistance of the cell?

285 / 360

Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

285. While verifying Ohm’s law experimentally, the slope of the $V-I$ graph is found to be 5 $\Omega$. What does this indicate?

286 / 360

Category: Factors affecting the resistance of a conductor

286. Which of the following materials has the lowest resistivity?

287 / 360

Category: Factors Affecting Resistance

287. A wire made of a certain material has a resistance of 10 $\Omega$ at 20°C. If the temperature coefficient of resistance for this material is $0.004 \, \text{K}^{-1}$ and the wire is heated to 70°C, what will be its new resistance?

288 / 360

Category: Combination of Resistors

288. A $6 \Omega$ resistor is connected in series with a parallel combination of two $3 \Omega$ resistors. What is the total equivalent resistance?

289 / 360

Category: Length of the Conductor

289. A wire of resistance $4 \, \Omega$ is stretched such that its length becomes twice its original length. What is its new resistance?

290 / 360

Category: Electrical Energy and Power Consumption

290. How many joules are there in 1 kilowatt-hour (kWh)?

291 / 360

Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

291. Which of the following does NOT obey Ohm’s law?

292 / 360

Category: Statement of Ohm’s Law:

292. (A) The current flowing through a conductor is directly proportional to the potential difference across it if physical conditions remain constant.
(R) Ohm’s law states that $V = IR$ where $R$ is the resistance of the conductor.

293 / 360

Category: Practical Applications of Electrical Concepts

293. An electric kettle is rated 2000 W - 220 V. What is the safe limit of current that can flow through the kettle while in use?

294 / 360

Category: Internal Resistance of a Cell

294. Which of the following factors increases the internal resistance of a cell?

295 / 360

Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

295. A conductor carries a current of 2 A. If $3 \times 10^{19}$ electrons pass through the conductor in 1 second, what is the magnitude of the charge on each electron?

296 / 360

Category: Factors affecting the resistance of a conductor

296. A wire of resistance $R$ is stretched to double its original length while keeping the volume constant. What will be its new resistance?

297 / 360

Category: Concept of Charge, Current, Potential, Potential Difference, and Resistance

297. A charge of $12\,C$ flows through a conductor in $4\,s$. What is the current flowing?

298 / 360

Category: Electrical Power and Energy

298. A device is labeled as "$200 W - 240 V$". What is the maximum safe current that can flow through this device without damaging it?

299 / 360

Category: Combination of Resistors

299. (A) In a series combination of resistors, the equivalent resistance is always greater than any individual resistor in the combination.
(R) The equivalent resistance in a series combination is the sum of all individual resistances.

300 / 360

Category: Length of the Conductor

300. (A) The resistance of a wire increases when its length is increased.
(R) Resistance is directly proportional to the length of the conductor.

301 / 360

Category: Internal Resistance of a Cell

301. (A) The terminal voltage of a cell decreases when more current is drawn from it.
(R) The internal resistance of the cell causes a voltage drop proportional to the current.

302 / 360

Category: Current (I)

302. A charge of $9.6 \times 10^{-18} \, \text{C}$ flows through a wire when a current of 3 mA passes through it. What is the time taken for this charge to flow?

303 / 360

Category: Electrical Power and Energy

303. A household uses a $2 kW$ air conditioner for 5 hours daily. If the cost of electricity is Rs.6 per $kWh$, what is the monthly (30 days) cost of running the air conditioner?

304 / 360

Category: Charge (Q)

304. Convert $5 \, \mu C$ to coulombs.

305 / 360

Category: Combination of resistors in series

305. Four resistors $R_1 = 2 \Omega$, $R_2 = 4 \Omega$, $R_3 = 6 \Omega$, and $R_4 = 8 \Omega$ are connected in series. A battery is connected across the combination, and the potential difference across $R_2$ is measured to be $8 V$. What is the total voltage supplied by the battery?
$V = IR_s$

306 / 360

Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

306. In an experiment, two wires are tested for Ohm’s law compliance. Wire X has a linear $V-I$ graph, while Wire Y shows a non-linear graph. Which statement is correct?

307 / 360

Category: Combination of resistors in parallel

307. If three resistors $R_1 = 1 \Omega$, $R_2 = 2 \Omega$, and $R_3 = 4 \Omega$ are connected in parallel across a battery, which resistor will have the highest current?

308 / 360

Category: Combination of Resistors

308. You have two resistors, $R_1 = 3\,\Omega$ and $R_2 = 6\,\Omega$, connected in parallel, and this combination is connected in series with a third resistor $R_3 = 2\,\Omega$. If the total voltage across the circuit is $10V$, what is the current through $R_3$?

309 / 360

Category: Resistors in Parallel:

309. (A) The equivalent resistance of three resistors $R_1$, $R_2$, and $R_3$ connected in parallel is less than the smallest individual resistance.
(R) In a parallel combination, the reciprocal of the equivalent resistance is equal to the sum of the reciprocals of individual resistances.

310 / 360

Category: Material of the Conductor

310. Which of the following materials would be most suitable for making a fuse wire?

311 / 360

Category: Ohm’s Law

311. A device shows a nonlinear $V-I$ curve with increasing current for increasing voltage but not following Ohm’s law. Which of the following devices could this likely represent?

312 / 360

Category: Combination of resistors in parallel

312. Three resistors of 2 Ω, 4 Ω, and 8 Ω are connected in parallel. What is their equivalent resistance?

313 / 360

Category: CHOICE OF MATERIAL OF A WIRE

313. (A) Silver is not commonly used for electrical wiring despite having lower specific resistance than copper.
(R) The high cost of silver makes it economically unviable for large-scale electrical wiring applications.

314 / 360

Category: Material of the Conductor

314. What is the formula for calculating specific resistance (\$\rho\$) of a material?

315 / 360

Category: Unit of Resistance

315. (A) The unit of resistance is ohm (\$\Omega\$).
(R) Ohm is defined as the resistance when 1 volt applied across a conductor produces 1 ampere current.

316 / 360

Category: Combination of Resistors

316. (A) The equivalent resistance of two resistors connected in parallel is always less than the smallest individual resistance.
(R) In a parallel combination, the reciprocal of the equivalent resistance is equal to the sum of the reciprocals of the individual resistances.

317 / 360

Category: Ohm’s Law

317. (A) Ohm’s law states that the current flowing through a conductor is directly proportional to the potential difference across its ends, provided the physical conditions remain constant.
(R) The resistance of a conductor remains constant as long as temperature and other physical conditions are unchanged.

318 / 360

Category: Factors affecting the resistance of a conductor

318. What happens to the resistance of a wire if its cross-sectional area becomes four times larger?

319 / 360

Category: Factors Affecting Internal Resistance:

319. How does the surface area of electrodes affect the internal resistance of a cell?

320 / 360

Category: Practical Applications of Electrical Concepts

320. A 60 W electric bulb is rated for 250 V. If the line voltage drops to 200 V, what will be the power consumed by the bulb?

321 / 360

Category: Statement of Ohm’s Law:

321. Which of the following devices does NOT obey Ohm's law?

322 / 360

Category: Charge (Q)

322. A metal sphere loses $3.125 \times 10^{18}$ electrons. What is the net charge acquired by the sphere?

323 / 360

Category: Factors Affecting Internal Resistance:

323. (A) Increasing the temperature of the electrolyte decreases the internal resistance of a cell.
(R) Higher temperature increases the mobility of ions in the electrolyte.

324 / 360

Category: Factors Affecting Resistance

324. (A) The resistance of a wire increases when its temperature is increased.
(R) The specific resistance of a metallic conductor increases with an increase in temperature.

325 / 360

Category: Resistors in Parallel:

325. What is the equivalent resistance when three resistors of $2\,\Omega$, $4\,\Omega$, and $8\,\Omega$ are connected in parallel?

326 / 360

Category: Combination of Resistors

326. Four identical resistors each of resistance $5\,\Omega$ are connected in parallel. If a current of $2\,A$ passes through the circuit, what is the potential difference across each resistor?

327 / 360

Category: Material of the Conductor

327. A wire made of manganin has a resistance of 100 $\Omega$ at room temperature. If the temperature is increased by 200$^\circ$C, what will be its new resistance? (Given: Manganin has negligible temperature coefficient of resistance.)

328 / 360

Category: Potential Difference (P.D.)

328. What is the potential difference between two points if 10 joules of work is done to move a charge of 5 coulombs from one point to another?

329 / 360

Category: EXPERIMENTAL VERIFICATION OF OHM’S LAW

329. Which of the following conditions must be satisfied to verify Ohm’s law accurately?

330 / 360

Category: Unit of Resistance

330. What is the definition of 1 ohm?

331 / 360

Category: Area of Cross-Section

331. (A) If the area of cross-section of a wire is doubled, its resistance becomes half.
(R) The resistance of a wire is inversely proportional to its area of cross-section.

332 / 360

Category: Statement of Ohm’s Law:

332. Two resistors $R_1 = 6\;\Omega$ and $R_2 = 3\;\Omega$ are connected in parallel to a battery providing $12V$. How does the current divide between them?

333 / 360

Category: Area of Cross-Section

333. A wire of length $l$ and cross-sectional area $A$ has a resistance of $8 \, \Omega$. If the wire is stretched such that its length becomes $2l$, what will be its new resistance? (Assume volume remains constant.)

334 / 360

Category: Factors Affecting Internal Resistance:

334. Which of the following statements is true about the distance between the electrodes and internal resistance?

335 / 360

Category: CHOICE OF MATERIAL OF A WIRE

335. Which material is most commonly used for making wires in electrical connections and power transmission due to its low specific resistance?

336 / 360

Category: Internal Resistance of a Cell

336. When is the terminal voltage of a cell equal to its e.m.f.?

337 / 360

Category: Factors affecting the resistance of a conductor

337. If the length of a wire is doubled while keeping all other factors constant, how does its resistance change?

338 / 360

Category: Factors Affecting Resistance

338. What happens to the resistance of a metallic conductor when its temperature increases?

339 / 360

Category: Current (I)

339. If a charge of $5 C$ flows through a conductor in 10 seconds, what is the current flowing through it?

340 / 360

Category: Material of the Conductor

340. Below which temperature does lead become a superconductor?

341 / 360

Category: Ohm’s Law

341. (A) The resistance of a conductor increases with an increase in temperature.
(R) As temperature rises, the free electrons collide more frequently with the lattice ions, increasing resistance.

342 / 360

Category: Statement of Ohm’s Law:

342. What is the mathematical statement of Ohm's Law?

343 / 360

Category: Internal Resistance of a Cell

343. Which of the following will decrease the internal resistance of a cell?

344 / 360

Category: Potential Difference (P.D.)

344. A battery with an e.m.f. of $12 \text{ V}$ supplies a current to a resistor. If the voltage drop inside the battery is $2 \text{ V}$, what is the energy dissipated per coulomb in the external circuit?

345 / 360

Category: Ohm’s Law

345. Which of the following materials is an example of an ohmic resistor?

346 / 360

Category: Current (I)

346. A conductor carries a current of 2 A. How many electrons pass through its cross-section in 5 seconds?

347 / 360

Category: Resistors in Parallel:

347. Two resistors of $4 \Omega$ and $12 \Omega$ are connected in parallel across a 12 V battery. What is the power dissipated by the $4 \Omega$ resistor?

348 / 360

Category: Charge (Q)

348. What happens when a body gains electrons?

349 / 360

Category: ELECTRICAL ENERGY

349. What is the power consumed by a device if it operates at 220 V and draws a current of 5 A?

350 / 360

Category: Combination of Resistors

350. Three resistors with resistances $R_1 = 2\,\Omega$, $R_2 = 4\,\Omega$, and $R_3 = 6\,\Omega$ are connected in series across a battery of emf 12 V. What is the potential difference across the $4\,\Omega$ resistor?

351 / 360

Category: CHOICE OF MATERIAL OF A WIRE

351. Below which temperature does lead become a superconductor?

352 / 360

Category: Combination of resistors in parallel

352. Four resistors, each of $5 \Omega$, are connected in parallel. What is their equivalent resistance?

353 / 360

Category: Resistors in Parallel:

353. Three resistors $R_1 = 2\Omega$, $R_2 = 4\Omega$, and $R_3 = 6\Omega$ are connected in parallel to a battery of emf 12V. What is the total current drawn from the battery?

354 / 360

Category: MEASUREMENT OF ELECTRICAL is ENERGY (EXPRESSION W = QV = Vit)

354. (A) The electrical energy dissipated by a resistor is directly proportional to the square of the current passing through it.
(R) According to Joule's law, the heat produced in a resistor is given by $H = I^2 R t$, where $I$ is the current and $R$ is the resistance.

355 / 360

Category: Internal Resistance of a Cell

355. A battery with emf $\epsilon$ and internal resistance $r$ is connected to an external load $R$. The efficiency of the battery is defined as the ratio of power delivered to the load to the total power generated by the battery. For what value of $R$ (in terms of $r$) will the efficiency be 50\%?

356 / 360

Category: Commercial Energy Consumption

356. A 2000 W electric geyser is used for 3 hours daily. If the cost of electricity is Rs.5 per kWh, what is the total cost for using the geyser for 30 days?

357 / 360

Category: Electrical Power and Energy

357. A bulb rated 60 W - 220 V is used for 5 hours daily. What is the energy consumed in kWh in 30 days?

358 / 360

Category: Electrical Power and Energy

358. (A) The power consumed by an electrical appliance rated 100 W - 220 V when connected to a 110 V supply is 25 W.
(R) The power consumed by an electrical appliance is directly proportional to the square of the voltage applied across it.

359 / 360

Category: Factors Affecting Internal Resistance:

359. A cell of emf 4.5 V and internal resistance $1.5 \Omega$ is connected to an external resistor of $6 \Omega$. If the current drawn from the cell is 0.6 A, what is the terminal voltage across the cell?

360 / 360

Category: Unit of Resistance

360. (A) The resistance of a conductor increases with temperature for all materials.
(R) The specific resistance of semiconductors decreases with temperature.

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