IGNITED MINDS

At- NUA POKHORI

WORKSHEET ON ELECTRICITY
Class 10 - Science

1. Following graph was plotted between V and I values, across a metal wire. Which of the following statement(s) [1]
is/are correct regarding this?

a) This graph illustrates the non-ohmic law. b) While plotting this graph, the temperature
remains constant.

c) Value of ratio V

1
when the potential d) All of these
difference in 0.8 V is not equal to the value
of ratio V

l
when the potential difference is
1.2 V.
2. Which of the following represents voltage? [1]
Work done Work done × Time
a) b)
Current × Time Current

c) Work done × Charge × Time d) Work done × Charge

3. The current passing through an electric kettle has been doubled. The heat produced will become: [1]

a) four times b) one-fourth

c) double d) half
4. If the current I through a resistor is increased by 100% (at constant temperature), the increase in power [1]
dissipated will be

a) 400% b) 300%

c) 100% d) 200%
5. The unit of electrical resistance is: [1]

a) Ampere b) Coulomb

c) Ohm d) Volt
6. A piece of wire of resistance 20Ω is drawn out so that its length is increased to twice its original length. [1]
Resistance of the wire in the new situation:

a) 70 Ω b) 50 Ω

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 c) 60 Ω d) 80 Ω
7. Which of the following obeys Ohm's law? [1]

a) Nichrom b) Filament of a bulb

c) LED d) Transistor
8. The resistors R1, R2, R3 and R4 in the given circuit are all equal in value and connected with a negligible [1]
resistance wire. Which of the following is correct relationship between the voltmeters readings V1, V2 and V3?

a) V1 = V2 < V3 b) V1 < V2 < V3

c) V1 = V2 > V3 d) V1 = V2 = V3

9. In a household, 250 unit electrical energy is consumed in particular months. In the standard unit, it means that [1]
the energy consumed is:

a) 250 KW/h b) 250 KJ

c) 250 kWh d) 500 kJ/h

10. In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W respectively are [1]
connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?

a) Brightness of bulb B will be more than that b) Brightness of bulb A will be the maximum
of A

c) Brightness of all the bulbs will be the same d) Brightness of bulb C will be less than that
of B
11. Let us consider the current flowing through a metallic wire if the temperature of the entire system increases. [1]
What will happen from the following options?

a) Resistance (R) decreases b) Potential difference (V) decreases

c) Potential difference (V) increases d) V and R remains the same

12. Which of the following does not apply to silver? [1]

a) The movement of electrons on their outer b) The resistance provided is directly

most orbital is tightly held together. proportional to its length.

c) Their resistivity is in the range 10-8 Ω to 10- d) The resistance provided is inversely
6 proportional to the area of cross section.
Ω .
13. A voltmeter and an ammeter are connected in series to an ideal cell of emf E. If the voltmeter reading is V, and [1]
the ammeter reading is I. Then
I. V < E
II. The voltmeter resistance is V

III. The potential difference across the ammeter is (E - V)

IV. Voltmeter resistance + ammeter resistance = E

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 a) III and IV b) I and II only

c) II and III only d) I, II, III, IV

14. The resistivity of a metallic wire depends on: [1]

a) Its shape b) Its thickness

c) Nature of material d) Its length

15. An electric room heater draws a current of 2.4A from the 120V supply line. What current will this room heater [1]
draw when connected to 240V supply line?

a) 5.8 amp b) 4.9 amp

c) 3.9 amp d) 4.8 amp

16. Which of the following does not represent electrical power? [1]
2

a) I2R b) V

c) IR2 d) VI

17. A heating coil has a resistance of 200Ω . At what rate will the heat be produced in it when a current of 2.5 A [1]
flows through it?

a) 1250 J/s b) 1200 J/s

c) 1350 J/s d) 600 J/s

18. The substance having infinitely high electrical resistance is called: [1]

a) Conductor b) Insulator

c) Resistor d) Superconductor
19. The unit for expressing electric power is: [1]

a) Coulomb b) Joule

c) Watt d) Volt
20. Two resistors of resistance 2 Ω and 4 Ω when connected to a battery will have [1]

a) same current flowing through them when b) same potential difference across them when
connected in series connected in series

c) different potential difference across them d) same current flowing through them when
when connected in parallel connected in parallel
21. When more than one resistors are in series, the quantity that remains same in them is [1]

a) Potential difference b) Ammeter

c) Resistance d) Current
22. An electric iron of 1500 W, 200 V and a flash light of 500 W, 200 V are used in homes. The rating of fuse to be [1]
used should be

a) 15 A b) 10 A

c) 20 A d) 5 A
23. An electric bulb is rated at 220V, 100W. What is its resistance? [1]

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 a) 454 ohm b) 384 ohm

c) 254 ohm d) 484 ohm

24. The resistance of a resistor is reduced to half of its initial value. If other parameters of the electrical circuit [1]
remain unaltered, the amount of heat produced in the resistor will become:

a) half b) two times

c) four times d) one fourth

25. When the diameter of a wire is doubled, its resistance becomes: [1]

a) Double b) Four times

c) One-fourth d) One-half
26. The minimum resistance which can be made using five resistors each of resistance 10Ω is : [1]

a) b)
1
Ω 2Ω
50

c) 1Ω d) 1

5
Ω

27. How much energy is does a 100W electric bulb transfer in 1 minute? [1]

a) 100 J b) 3600 J

c) 6000 J d) 600 J

28. If the charge on an electron is 1.6 × 10-19 coulombs, how many electrons should pass through a conductor in 1 [1]

second to constitute 1 ampere current?

a) 6.25 × 10-18 b) 6.35 × 10-18

c) 6.15 × 10-17 d) 6.25 × 10-19

29. An electric fan runs from the 230V mains. The current flowing through it is 0.4A. At what rate is electrical [1]
energy transferred by the fan?

a) 91 J/s b) 93 J/s

c) 92 J/s d) 95 J/s
30. The work done in moving a unit charge across two points in an electric circuit is a measure of: [1]

a) Potential difference b) Power

c) Resistance d) Current
31. An air conditioner is rated 260 V, 2.0 kW. The air conditioner is switched on for 10 hours each day. What is [1]
electrical energy consumed in 30 days?

a) 600 kW h b) 420 kW h

c) 20 kW h d) 2000 kW h
32. An electric bulb rated 220 V, 60 W is working at full efficiency. Another identical bulb is connected in the same [1]
circuit having power supply of 220 V.
i. If both the bulbs are connected in series then the total power consumption will be 60 W.
ii. If only one bulb is connected then the total power consumption will be 30 W.
iii. If the both bulbs are connected in parallel then the total power consumption will be 120 W.
Which of the above statement(s) is/are correct regarding the circuit?

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 a) Only (iii) b) Only (ii) and (iii)

c) Only (i) and (ii) d) Only (i)

33. While performing the experiment to study the dependence of current on potential difference, if the circuit used to [1]
measure the current and voltage is kept on a position for a longer time, then:

a) All of these b) Ammeter reading will change

c) The resistor will get heated up changing the d) Voltmeter reading will change
value of "R"
34. An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be [1]
used for it?

a) 4 A b) 1 A

c) 5 A d) 2 A
35. If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the [1]
increase in power dissipated will be

a) 200 % b) 400 %

c) 300 % d) 100 %
36. The resistivity of copper metal depends on only one of the following factors. This factor is: [1]

a) Thickness b) Temperature

c) Length d) Area of cross-section

37. The ammeter is used to measure the current flowing in the circuit. It is always connected in series with resistor [1]
because:

a) It has high resistance b) It has low melting point

c) It has no resistance d) It has low resistance

38. Which of the following terms does not represent electrical power in a circuit? [1]
2

a) V
b) VI
R

c) IR2 d) I2R

39. A wire of resistance R is cut into five equal pieces. These pieces are connected in parallel and the equivalent [1]
resistance of the combination is R'. Then the ratio R

′
is:
R

a) 25:1 b) 5:1

c) 1:25 d) 1:5
40. Two bulbs of 100 W and 40 W are connected in series. The current through the 100 W bulb is 1 A. The current [1]
through the 40 W bulb will be:

a) 1 A b) 0.4 A

c) 0.8 A d) 0.6 A
41. There is a dual of 8 ohm resistance on the aerial. Determine the aerial's new resistance. [1]

a) 10 Ω b) 2 Ω

c) 7 Ω d) 4 Ω

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42. The elements of electric heating devices are usually made of: [1]

a) nichrome b) bronze

c) argon d) tungsten
43. An electric fuse works on the: [1]

a) chemical effect of current b) lighting effect of current

c) heating effect of current d) magnetic effect of current

44. The resistance of the conductor is R. If the length is doubled by stretching the wire, then its new resistance will [1]
be:

a) R b) 4R

c) 8R d) 2R
45. The unit of resistivity is [1]

a) ohm-m b) mho

c) ohm d) ohm/m
46. A metallic conductor has loosely bound electrons called free electrons. The metallic conductor is: [1]

a) Positively charged b) Negatively charged

c) Neutral d) Either positively charged or negatively

charged
47. Which of the following is the most likely temperature of the filament of an electric light bulb when it is working [1]
on the normal 220 V supply line?

a) 2500°C b) 1500°C

c) 500°C d) 4500°C
48. In which of the following network of resistors the equivalent resistance between points A and B is highest? [1]

a) All have equal equivalent resistance. b) Network (iii)

c) Network (i) d) Network (ii)

R1
49. R1 and R2 are two resistors and r1 and r2 are equivalent resistances in series and parallel respectively, then = [1]
R2

r1 r2 r1 +r2
a) r1 +r2
b) r1 r2

c) r1 +√r1 −4r1 r2
d) r1 +√r1 −4r1 r2

r1 −√r1 −4r1 r2 r1 +√r1 +4r1 r2

50. How many electrons are flowing per second past a point in a circuit in which there is a current of 5A? [1]

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 a) 31.25 × 1017C b) 31.25 × 1019C

c) 31.25 × 1018C d) 31.25 × 1015C

51. When the area of cross-section of a conductor is doubled, its resistance becomes: [1]

a) Half b) Four times

c) Double d) One-fourth
52. A current of 5 amperes flows through a wire whose ends are at a potential difference of 3 volts. The resistance of [1]
the wire:

a) 0.7 Ohms b) 0.1 Ohms

c) 0.6 Ohms d) 0.5 Ohms

53. The lamps in a household circuit are connected in parallel because: [1]

a) this way they required less current b) if one lamp fails the others also fail

c) if one lamp fails the others remain lit d) this way they require less power
54. How many joules of electrical energy are transferred per second by a 6 V, 0.5 A lamp? [1]

a) 30 J/s b) 3 J/s

c) 0.83 J/s d) 12 J/s

55. The device used for measuring potential difference is known as: [1]

a) Voltmeter b) Galvanometer

c) Ammeter d) Potentiometer
56. The heat produced in a wire of resistance x when a current y flows through it in time z is given by: [1]

a) y × z × x b) x2 × y × z

c) x × z × y2 d) y × z2 × x

57. In a house, two 60W electric bulbs are lighted for 4 hours and three 100W bulbs for 5 hours every day. The [1]
electric energy is consumed in 30 days:

a) 59.4 kWh b) 79.4 kWh

c) 100 kWh d) 45 kWh

58. The commercial unit of energy is: [1]

a) Kilo-joule b) Kilowatt-hour

c) Watt-hour d) Watt
59. An electric kettle consumes 1 kW of electric power when operated at 220 V. The minimum rating of the fuse [1]
wire to be used for it is

a) 1 A b) 5 A

c) 2 A d) 4 A
60. If 20C of charge pass a point in a circuit in 1s, what current is flowing? [1]

a) 40A b) 30A

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 c) 20A d) 20C
61. At a given time, a house is supplied with 100 A at 220 V. How many 75 W, 220 V light bulbs could be switched [1]
on in the house at the same times if they are all connected in parallel?

a) 93 b) 293

c) 193 d) 393
62. Study the following statements: [1]
a. A fuse in a circuit prevents damage to the circuit due to overloading.
b. Total resistance in a circuit increases due to overloading.
c. During short circuiting the current in the circuit abruptly increases.
d. In order that each appliance has same current, they are connected in parallel to each other.
The correct statements are

a) (b) and (d) b) (a) and (c)

c) (a), (c) and (d) d) (a) and (b)

63. How much energy is consumed when a current of 5 ampere flows through the filament of a heater having a [1]
resistance of 100 ohms for two hours? Express it in joules.

a) 18 × 105 J b) 18 × 106 J

c) 18 × 107 J d) 18 × 109 J

64. The resistivity of the conductor does not depend upon its length or thickness because it is the: [1]

a) Independent to thickness b) Independent to length

c) Nature of material d) Depends upon altitude

65. Study the I-V graph for three resistors of resistances R1, R2 and R3 and select the correct statement from the [1]
following:

a) R2 > R3 > R1 b) R1 > R2 > R3

c) R1 = R2 = R3 d) R3 > R2 > R1

66. A student has correctly set-up the circuit for finding the equivalent resistance of two resistors in parallel. Each [1]
terminal of each of the two resistors, in this circuit, would be connected to

a) at least four more components in the circuit. b) at least two more components in the circuit.

c) only one more component in the circuit. d) at least three more components in the
circuit.
67. A cylindrical conductor of length l and uniform area of cross section A has resistance R. The area of cross [1]
section of another conductor of same material and same resistance but of length 2l is

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 a) A

2
b) 2A

c) 3A d)
3A

68. If the area of cross-section of a resistance wire is halved, then its resistance becomes: [1]

a) 4 times b) One-half

c) 2 times d) One-fourth
69. A car headlight bulb working on a 12V car battery draws a current of 0.5 A. The resistance of the light bulb is: [1]

a) 0.5 Ω b) 6 Ω

c) 12 Ω d) 24 Ω
70. Six equal resistances are connected between points P, Q and R as shown in the figure. The net resistance will be [1]
maximum between

a) P and Q b) P and R

c) Any two points. d) Q and R

71. The potential difference across a 3Ω resistor is 6V. The current flowing in the resistor will be: [1]

a) 6 A b) 2 A

c) 1 A d) A
1

72. What possible values of resultant resistance one can get by combining two resistances, one of value 2 ohm and [1]
the other 6 ohm?

a) 8 ohm b) 5 ohm

c) 10 ohm d) 6 ohm
73. Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series [1]
and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and
parallel combinations would be-

a) 1 : 2 b) 4 : 1

c) 2 : 1 d) 1 : 4
74. How much work is done in moving a charge of 3 C across two points having a potential difference of 12 V? [1]

a) 36 J b) 216 J

c) 54 J d) 4 J
75. An electric heater is rated at 1500 W. How much heat is produced per hour? [1]

a) 5.4 × 106 J b) 5400 J

c) 5.4 × 105 J d) 54000 J

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