CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A

1. Constantan or Manganin wire is used for making standard resistance because they have:
a. Low specific resistance
b. High specific resistance
c. Negligible temperature coefficient of resistance
d. High melting point
2. A potential difference is applied across the ends of a metallic wire. If the potential difference
is doubled, the drift velocity:
a. Will be doubled c. Will be quadrupled
b. Will be halved d. Will remain unchanged
3. The resistor R1 dissipates power P when connected to a generator. If a resistor R2 is inserted
in series with R1, the power dissipated by R1:
a. Increases
b. Decreases
c. Remains the same
d. May decrease or increase depending on the values of R1 and R2
4. * The masses of three wires of copper are in the ratio of 1: 3: 5 and their lengths are in the
ratio 5: 3: 1. The ratio of their electrical resistances is:
a. 1: 3: 5 c. 1: 15: 125
b. 5: 3: 1 d. 125: 15: 1
5. Kirchhoff’s first law is based on the law of conservation of:
a. Charge c. Momentum
b. Energy d. Sum of mass and energy
6. Kirchhoff’s second law is based on the law of conservation of:
a. Charge c. Momentum
b. Energy d. Sum of mass and energy
7. There is a current of 6.4 ampere in a conductor. The number of electron that any cross section
normal to the direction of flow per second, is:
a. 3 × 1019 c. 4 × 1019
b. 2 × 10 19 d. 7.86 × 1020
8. Six cells, each of EMF (E) and internal resistance r are connected in series. If due to oversight,
one cell is connected wrongly, then the equivalent EMF and internal resistance of the
combination is:
a. 6E and 6r c. 4E and 6r
b. 4E and 4r d. 5E and 3r
9. * Five identical lamps, each of resistance 1100 ohm are connected to 220 V as shown in the
following figure. The reading of an ideal ammeter is:

220 220
a. 1100 × 5 amp c. 1100 × 1 amp
220 220
b. 1100 × 3 amp d. 1100 × 2 amp
10. A standard 40 watt tube light is in parallel with a room heater both connected to a suitable
main AC supply line. What will happen when the light is switched off?
a. The heater output will be larger b. It will be smaller

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
c. It will remain the same d. None of the above
11. The wire of the electric fire element glows red hot but the copper wire in the leads from the
plug remain cool, although the same current is passing through each. This is because the
element wire:
a. None of these
b. Has much higher resistance than the copper wire
c. Is coiled but the copper wire is not
d. Has a much lower resistance than the copper wire
12. A current flows in a wire of circular cross section with the free electrons travelling with a
mean drift velocity 𝐯⃗. If an equal current flows in a wire of thrice the radius, new more drift
velocity is:
a. 3v⃗ c. v
⃗ /9
b. v
⃗ /3 d. None of these
13. A current I flows through a uniform wire of diameter d, when the drift velocity is 𝐯𝐝 . The
same current will flow through a wire diameter d/2 made of the same material if the mean
drift velocity of the electrons is:
a. v/4 c. 4v
b. v/4 d. 2v
14. The resultant resistance value of (n) resistances, each of (r) ohm when connected in parallel,
is (x). When these n resistances are connected in series, the resultant value is:
a. nx c. rnx
b. n x
2 d. r2x/n
15. A cell of EMF E is connected across a resistance r. The potential difference between the
terminals of the cell is found to be V. The internal resistance of the cell must be:
2(E−V)V (E−V)r
a. c.
r V
b.
2(E−V)r d. (E – V) r
E
16. A wire of resistance R is stretched till its radius is half of the original value. Then, the
resistance of the stretched wire is:
a. 2R c. 8R
b. 4R d. 16R
17. A wire of resistance R is stretched till its length is double of the original value. Then, the
resistance of the stretched wire is:
a. 2R c. 4R
b. 8R d. 16R
18. * Two square metal plates A and B are of same thickness and material. The side of B is twice
that of A. These are connected as shown in series. If the resistance of A and B are denoted by
RA and RB, then (RA/RB) is:

a. 1/2 c. 1/1
b. 2/1 d. 4/1

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
19. * The dimensions of block are 1 cm × 1 cm × 100 cm. If the specific resistance of its material
is 3 × 10-7 ohm × meter, then the resistance between the opposite rectangular faces is:
a. 3 × 10-9 ohm c. 3 × 10-5 ohm
b. 3 × 10 ohm
-7 d. 3 × 10-3 ohm
20. * In the above question, the resistance between the square faces is:
a. 3 × 10-9 ohm c. 3 × 10-5 ohm
b. 3 × 10-7 ohm d. 3 × 10-3 ohm
21. A cell of EMF (E) and internal resistance r is connected in series with an external resistance
nr. Then the ratio of the terminal potential difference to EMF is:
a. (1/n) c. n/(n + 1)
b. 1/(n + 1) d. (n + 1)/n
22. Four wires of equal length and resistance 5 ohm each are connected in the form of a square.
The equivalent resistance between the diagonally opposite corners of the square is:
a. 5 ohm c. 20 ohm
b. 10 ohm d. 5/4 ohm
23. The resistances in the following figure are in ohm. Then, the effective resistance between the
points A and B is:
a. 3 Ohms
b. 2 Ohms
c. 6 Ohms
d. 36 Ohms

24. In the following figure, the equivalent resistance between A and B is:

a. 17/24 Ohms
b. 4/3 Ohms
c. 29 Ohms
d. 24/17 Ohms

25. Twelve equal resistors, each of resistance R, are connected to form a Skelton cube. Then, the
equivalent resistance taken between two diagonally opposite corners is:
a. R c. 5R/6
b. 12R d. 7R/12
26. The value of current I in the following circuit is:

a. 3 Amperes
b. 13 Amperes
c. 23 Amperes
d. -3 Amperes

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
27. A current of 5 A exists in a 10 ohm resistance for 4 min. How many coulombs pass through
any cross section of the resistor in this time?
a. 12 c. 1200
b. 120 d. 12000
28. * Eels are able to generate current with biological cells called electro plaques. The electro
plaques in an eel are arranged in 100 rows, each row stretching horizontally along the body
of fish containing 5000 electro plaques. The arrangement is suggestively shown in the figure.
Each electro plaque has an EMF of 0.15 V and internal resistance of 0.25 𝛀. The water
surrounding the eel completes a circuit between the head and its tail. If the water
surrounding it has a resistance of 500 𝛀. The current an eel can produce in water is about:

a. 3.0 Amperes
b. 1.5 Amperes
c. 15 Amperes
d. 30 Amperes

29. The temperature coefficient of resistance of a wire is 0.00125℃−𝟏. At 300 K its resistance is
one ohm. The resistance of the wire will be 2 ohm at:
a. 1154 K c. 1400 K
b. 1100 K d. 1127 K
30. * You are given several identical resistances each of value R = 10 𝛀 and each capable of
carrying a maximum current of one ampere. It is required to make a suitable combination of
these resistances of 5 𝛀 which can carry a current of 4 ampere. The minimum number of
resistances of the type R that will be required for this job is:
a. 4 c. 8
b. 10 d. 20
31. A current 2 amp falls in a system of conductors as shown in the following figure. The
potential difference between (VA – VB) will be (in volt):

a. + 2 Volts
b. + 1 Volts
c. - 2 Volts
d. - 1 Volts

32. * An electric cable of copper has just one wire of radius 9 mm. Its resistance is 5 ohm. This
single copper wire of the cable is replaced by 6 different well insulated copper wires each of
radius 3 mm. The total resistance of the cable will now be equal to:
a. 7.5 Ω c. 90 Ω
b. 45 Ω d. 270 Ω

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
33. Four resistors 40 𝛀, 60 𝛀, 90 𝛀 and 110 𝛀 are connected to a battery of EMF 4 volt and
negligible internal resistance as shown in the following figure. Then, the potential difference
between the points B & D is:

a. + 1 Volts
b. + 0.2 Volts
c. – 0.2 Volts
d. - 1 Volts

34. In the following figure, the reading of the ammeter A, when the internal resistance of the
battery is zero, is:
a. 20/3 Amperes
b. 20/4 Amperes
c. 20/12 Amperes
d. (20/4 + 20/12) Amperes

35. In the above question, the reading of the ammeter A, when the internal resistance of the
battery is 2 ohm, is:
a. 5 amp c. 1 amp
b. 3 amp d. 4 amp
36. There is a current of 40 amp in a wire of 10-6 square meter area of cross section. If the
number of free electrons per cubic meter is 1029, then the drift velocity is:
a. 250 × 10-3 m/s c. 2.50 × 10-3 m/s
b. 25.0 × 10-3 m/s d. 1.25 × 103 m/s
37. The current in the branch CD in the circuit shown below will:

a. I1 + I2 Amperes
b. I2 + I3 Amperes
c. I1 + I3 Amperes
d. I1 - I3 Amperes

38. When a resistance of 2 ohm is connected across the terminals of a cell, the current is 0.5 amp.
When the resistance is increased to 5 ohm, the current is 0.25 amp. The EMF of the cell is:
a. 1.0 volt c. 1.5 volt
b. 2.0 volt d. 2.5 volt
39. Resistances of 1, 2 and 3 ohms are connected in the form of a triangle. If a 1.5 volt cell of
negligible internal resistance is connected across 3 ohm resistor then current flowing
through this resistance will be:
a. 0.25 amp c. 0.5 amp
b. 1.0 amp d. 1.5 amp

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
40. Two wires of same material have same length but their cross sections are in the ratio 3: 1.
They are joined in series. The resistance of the thicker wire is 10 𝛀. The total resistance of
the combination will be:
a. 5/2 Ω c. 40 Ω
b. 40/3 Ω d. 100 Ω
41. In the given current distribution, what is the value of I?

a. 3 Amperes
b. 2 Amperes
c. 5 Amperes
d. 8 Amperes

42. * Two identical cells connected in series send 10 amp current through a 5 𝛀 resistor. When
they are connected in parallel, they send 8 amp current through the same resistance. What
is the internal resistance of each cell?
a. Zero c. 10 Ω
b. 2.5 Ω d. 1.0 Ω
43. * The lamp of a flash light is of 1.5 𝛀 resistance. It uses 3 cells each of 1.5 V and internal
resistance 0.25 𝛀. What is the net potential difference across the lamp?
a. 1.5 V c. 3 V
b. 2.25 V d. 4.5 V
44. * Two flash light electric incandescent lamps, each requiring 3 amps at 1.5 V are placed in
series and connected to a 6 V cell having negligible internal resisitance. What resistance
must be connected to series to operate them?
a. 22 Ω c. 6 Ω
b. 2 Ω d. 1 Ω
45. * The number of dry cells, each of EMF 1.5 volt and internal resistance 0.5 𝛀 that must be
joined in series with a resistance of 20 ohm so as to send a current of 0.6 ampere through the
circuit is:
a. 2 c. 10
b. 8 d. 12
46. A potential difference V is applied to a conductor of length l and radius r. When potential
difference is doubled, the drift velocity is:
a. Halved c. Doubled
b. Unchanged d. Quadrupled
47. * A hollow copper tube of 5 meter length has got external diameter equal to 10 cm and its
walls are 5 mm thick. The specific resistance of copper is 1.7 × 10-8 ohm × meter. The
resistance of the copper tube approximately is:
a. 5.6 × 10-3 Ω c. 5.6 × 10-5 Ω
b. 5.6 × 10-9 Ω d. 5.6 × 10-7 Ω
48. Thermal speed of free electrons is of order of:
a. Zero c. 105 m/s
b. 10-2 cm/s d. 10-4 m/s
49. Drift speed of electrons is of order of:
a. Zero b. 10-2 cm/s

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
c. 105 m/s d. 100 m/s
50. The wire has resistance 16 𝛀. It is bent in the form of a circle. The effective resistance
between two points on any diameter of the circle is:
a. 32 Ω c. 8 Ω
b. 24 Ω d. 4 Ω
51. * Two batteries of different EMF and internal resistance are connected in series with each
other and with an external load resistor. The current 3.0 ampere. When the polarity of one
battery is reversed, the current becomes 1.0 amp. The ratio of the EMF of the two batteries
is:
a. 2.5 c. 1.5
b. 2.0 d. 1.0
52. In the circuit diagram shown below, the magnitude and direction of the flow of current
respectively would be:

a. 7/3 amp from a to b via e c. 1.0 amp from b to a via e

b. 7/3 amp from b to a via e d. 1.0 amp from a to b via e
53. Four resistors are connected as shown in the following figure. A 6 V battery of negligible
resistance is connected across terminals A and C. The potential difference across terminals
B and D will be:
a. 2 Volts
b. 0 Volts
c. 3 Volts
d. 1.5 Volts

54. What will be the equivalent resistance between the two points A and D?

a. 20 Ohms
b. 30 Ohms
c. 10 Ohms
d. 40 Ohms

55. In the adjoining circuit shown the potential difference between points A and B will be:

a. 2 Volts
b. 2/3 Volts
c. 8/9 Volts
d. 4/3 Volts

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
56. In the adjoining figure the EMF of the cell is 2 V and internal resistance is negligible. The
resistance of the voltmeter is 80 ohm. The reading of voltmeter will be:

a. 2.00 Volts
b. 1.33 Volts
c. 1.60 Volts
d. 0.80 Volts

57. In the adjoining figure, current through 3𝛀 resistor is 0.8 amp; then the potential drop
through 4𝛀 resistor is:

a. 1.20 Volts
b. 4.80 Volts
c. 9.60 Volts
d. 2.65 Volts

58. Pieces of aluminum (Al) and germanium (Ge) are cooled from T1 K to T2 K. The resistance of:
a. Each of them increases
b. Each of them decreases
c. Aluminum increases and that of germanium decreases
d. Aluminum decreases and that of germanium increases
59. * sA uniform wire of resistance 20 ohm having resistance 1𝛀/m is bent in the adjoining form
of a circle as shown in the figure. If the equivalent resistance between M and N is 1.8 𝛀, then
the length of the shorter section is:

a. 1.80 m
b. 2.00 m
c. 18.0 m
d. 5.00 m

60. The equivalent resistance of network shown in the figure between the points A and B is:

a. 6 Ohms
b. 8 Ohms
c. 16 Ohms
d. 24 Ohms

61. A conductor of resistance 3 𝛀 is stretched uniformly till in length is doubled. The wire is now
bent in the form of an equilateral triangle. The effective resistance between the ends of any
side of the triangle (in ohm) is:
a. 9/2 b. 8/3
c. 2/3 d. 12

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CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
62. A uniform conductor of resistance R is cut into 20 equal pieces. Half of them are joined in
series and the remaining half of them are connected in parallel. If the two combinations are
joined in series, the effective resistance will be:
a. R c. 101 R/200
b. R/2 d. 201 R/200
63. When a current flows in a wire, there exists in an electric field in the direction of:
a. Flow of conventional current
b. Opposite to the flow of conventional current
c. Perpendicular to the flow of conventional current
d. At an angle of 45° to the flow of conventional current
64. The drift velocity of free electrons in a conductor is 𝐯 when a current I is flowing in it. If both
the radius and current are doubled, the drift velocity will be:
a. v c. v/4
b. v/2 d. v/8
65. * The sides of a rectangular block are 2 cm, 3 cm and 4 cm. The ratio of maximum to minimum
resistance between its parallel faces is:
a. 4/1 c. 1/4
b. 2/1 d. 1/2
66. Three equal resistances each of 3 𝛀 are in series and connected to a cell of internal resistance
one ohm. If these resistances are in parallel and connected to the same cell, then the ratio
of the respective currents through the electric circuits in two cases is:
a. 1/8 c. 1/5
b. 1/7 d. 1/3
67. Find the equivalent resistance across AB. Each resistance is of 2 ohms:

a. 2 Ohms
b. 1 Ohms
c. 3 Ohms
d. 4 Ohms

68. * Two different conductors have same resistance at 0℃. It is found that the resistance of the
first conductor at t1℃, is equal to the resistance of the second conductor at t2℃. The ratio
of the temperature coefficients of resistance of the conductors, 𝛂𝟏 ⁄𝛂𝟐 is:
t t −t
a. t1 c. 2t 1
2 1
t2 −t1 t2
b. d. t
t2 1
69. * In the circuit, the potential difference across PQ will be nearest to:

a. 9.60 Volts
b. 3.20 Volts
c. 6.60 Volts
d. 4.80 Volts

70. * Two identical cells of the same EMF and same internal resistance give the same current
through an external resistance of 2𝛀, regardless whether they are connected in series or
parallel. Internal resistance of the cell will be:
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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
a. 0.5 Ω c. 2 Ω
b. 1 Ω d. 3 Ω
71. In the circuit shown here, the readings of the ammeter and voltmeter are. Battery is of 6
volts and internal resistance is of 1 ohms:

a. 6A, 60V b. 0.6A, 6V

11 11 6 60
c. 6 A, 60V d. 11A, 11V
72. * Equal potentials are applied on an iron and a copper wire of same length. In order to have
the same current flow in the two wires, the ratio r (iron)/r (copper) of their radii must be
about: (Given that: specific resistance of iron = 1.0 × 10-7 ohm-m and specific resistance of
copper = 1.7 × 10-8 ohm-m)
a. 1.2 c. 3.6
b. 2.4 d. 4.8
73. The internal resistance of a cell of EMF 2V is 0.1 𝛀. It is connected to a resistance of 3.9 𝛀.
The voltage across the cell will be:
a. 0.5 V c. 1.95 V
b. 1.9 V d. 2 V
74. In which one of the following substances, the resistance decrease with increase of
temperature?
a. Carbon c. Silver
b. Copper d. Gold
75. For a cell the terminal potential difference is 2.2 V when the circuit is open and reduces to
1.8 V when the cell is connected to a resistance R = 5𝛀. The internal resistance of cell (r) is:
10 11
a. 9 Ω c. 9 Ω
9 9
b. 10 Ω d. 11 Ω
76. A fuse wire is a wire of:
a. Low resistance and low melting point c. Low resistance and high melting point
b. High resistance and low melting point d. High resistance and high melting point
77. If the ammeter in the given circuit reads 2A, the resistance R is:

a. 2 Ohms
b. 1 Ohms
c. 3 Ohms
d. 4 Ohms

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78. In the circuit shown, find current I1 & I2 is (Kirchhoff’s Law Applications):

a. 1.6 , 3.8 A
b. 1.8 , 3.4 A
c. 1.2 , 4.0 A
d. 1.0 , 4.2 A

79. For a metallic wire, the ratio V/I (V = applied potential difference, I = Current flowing):
a. Increases or decreases as the temperature rises, depending upon the metal
b. Decreases as the temperature rises
c. Is independent of temperature
d. Increases as the temperature rises
80. * Three unequal resistors in parallel are equivalent to a resistance 1 ohm. If two of them are
in the ratio 1 : 2 and if no resistance value is fractional, the largest of the three resistances
(in ohm) is:
a. 4 c. 5
b. 6 d. 12
81. A 3 volt battery with negligible internal resistance is connected in a circuit as shown in the
adjoining figure. The current I in the circuit will be:

a. 1/3 amp c. 1.5 amp

b. 1 amp d. 2 amp
82. The electric resistance of a certain wire of iron is R. If its length and radius are both doubled,
then:
a. The resistance will be doubled and the specific resistance will be halved
b. The resistance will be halved and the specific resistance will remain unchanged
c. The resistance will be halved and the specific resistance will be doubled
d. The resistance and the specific resistance will both remain unchanged
83. The total current supplied to the circuit by the battery is:

a. 1 A c. 4 A
b. 2 A d. 6 A

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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
84. * An electric current is passed through a circuit containing two wires of the same material
connected in parallel. If the lengths and radii of the wires are in the ratio of 4/3 and 2/3,
then the ratio of currents passing through the wires will be:
a. 3/1 c. 8/9
b. 1/3 d. 2/1
85. Six equal resistances are connected points P, Q and R as shown in the adjoining figure. Then,
the net resistance will be maximum between:

a. P and Q c. P and R
b. Q and R d. Any two points
86. The temperature coefficient of resistivity of a material is 4 × 10-4/K. When the temperature
of material is increased by 50℃, its resistivity increases by 2 × 10-8 𝛀m. The initial
resistivity of material (in ohm meter) is:
a. 50 × 10-8 c. 100 × 10-8
b. 90 × 10-8 d. 200 × 10-8
87. * A cell of EMF 3.4 V and internal resistance 3 𝛀 is connected to an ammeter of resistance 2
𝛀 and to an external resistance of 100 𝛀. A voltmeter is connected across the 100 𝛀 resistor.
The ammeter reads 0.04 A. What are the voltmeter reading and its resistance and what
would be its reading, if the voltmeter is ideal?
a. 3.2 V, 400 Ω and 3.24 V c. 6.4 V, 800 Ω and 6.48 V
b. 4.8 V, 600 Ω and 4.86 V d. 8 V, 900 Ω and 8 V
88. * A battery of EMF 1.4 V and internal resistance 2 𝛀 is connected to a resistance of 100 𝛀
through an ammeter. The resistance of the ammeter is 4/3 𝛀. A voltmeter is connected
across the 100 𝛀 resistance. If the current in the circuit is 0.02 A, what is the resistance of
voltmeter? If the voltmeter reads 1.1 V, what is the error in the reading?
a. 200 Ω , – 0.23 V c. 600 Ω , – 0.69 V
b. 400 Ω , + 0.46 V d. 800 Ω , + 0.92 V
89. * A, B and C are voltmeters of resistance R, 1.5 R and 3 R respectively. When same potential
difference is applied between x and y, the voltmeter readings are VA, VB and VC. Then:

a. VA = VB = VC c. VA = VB ≠ VC
b. VA ≠ VB = VC d. VA + VB = VC
90. * An ammeter and voltmeter are joined in series to a cell. The readings are x and y
respectively. If a resistance is joined in parallel with voltmeter:
a. Both x and y will increase c. x will decrease and y will increase
b. Both x and y will decrease d. x will increase and y will decrease

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91. The current in a simple series circuit is 5.0 amp. When an additional resistance of 2.0 ohm is
inserted, the current drops to 4.0 amp. The original resistance of the circuit (in ohm) was:
a. 1.25 c. 10
b. 8 d. 20
92. In the given circuit, given E = 6.0 V, R1 = 100 ohm, R2 = R3 = 50 ohm, R4 = 75 ohm. The
equivalent resistance of the circuit (in ohm) is:

a. 11.875 c. 118.75
b. 26.31 d. None of these
93. * By using only two resistance coils, singly in series or in parallel one should be able to obtain
resistances of 3, 4, 12 and 16 ohm. The separate resistances of the coil are:
a. 3 Ω and 4 Ω c. 12 Ω and 16 Ω
b. 4 Ω and 12 Ω d. 16 Ω and 3 Ω
94. The magnitude of I (in ampere) is:

a. 0.3 A
b. 0.1 A
c. 0.6 A
d. 0.8 A

95. Two wires that are made of two different materials whose specific resistances are in the ratio
2 : 3, length 3 : 4 and area 4 : 5. The ratio of their resistances is:
a. 6 : 5 c. 5 : 8
b. 6 : 8 d. 1 : 2
96. * In the adjoining circuit, if a conducting wire is connected between points A and B, the
current in this wire will:

a. Flow from B to A
b. Flow from A to B
c. Flow in the direction which will be decided by the value of V
d. Be zero
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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
97. A battery of EMF 10 V and internal resistance 3 ohm is connected to a resistor. The current
in the circuit is 0.5 amp. The terminal voltage of the battery when the circuit is closed, is:
a. 10 V c. 1.5 V
b. Zero d. 8.5 V
98. * In the adjoining circuit, the value of I (in ampere) is:

a. 1.5 A
b. 0.4 A
c. 0.7 A
d. 1.0 A

99. * A current of 6 A enters from one corner P of an equilateral triangle PQR having 3 wires of
resistance 2 𝛀 each and leaves by the corner R. Then, the currents I1 and I2 are:

a. 2A,4A
b. 4A,2A
c. 1A,5A
d. 2A,3A

100. A piece of copper and another of silicon are cooled from room temperature to 40 K. The
resistance:
a. Each of them increases
b. Copper increases and silicon decreases
c. Copper decreases and silicon increases
d. Each of them decreases
101. You are given (n) resistors, each of resistance r. They are first combined to get minimum
possible resistance, then they are connected to get maximum possible resistance. The ratio
between minimum to maximum resistance is:
a. 1/n c. n2
b. N d. 1/n2
102. A material (B) has twice the specific resistance as of (A). A wire made of B has twice the
diameter of a wire made of A. Then, for the two wires to have the same resistance, the ratio
LB/LA of their respective lengths must be:
a. 2 c. ½
b. 4 d. ¼
103. The resistance of a bulb filament is 100 𝛀 at a temperature of 100℃. If its temperature
coefficient of resistance be 0.005/℃, its resistance will become 200 𝛀 at a temperature of:
a. 200℃ c. 600℃
b. 400℃ d. 500℃

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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
104. * Two identical cells whether connected in parallel or in series give the same current when
connected to an external resistance 1.5 𝛀. Find the value of internal resistance of each cell.
a. 1.0 Ω c. 1.5 Ω
b. 0.5 Ω d. 2.0 Ω
105. * 32 cells, each of EMF 3V, are connected in series and kept in a box. Externally, the
combination shows an EMF of 84 V. The number of cells reversed in the combination is:
a. 0 c. 4
b. 2 d. 8
106. The ratio of the resistance of conductor at temperature 15℃ to its resistance at
temperature 37.5℃ is 4 : 5. The temperature coefficient of resistance of the conductor is:
1 1
a. 25 /℃ c. 80 /℃
1 1
b. 50 /℃ d. 75 /℃
107. In the adjoining circuit, the potential difference across 3 𝛀 is:

a. 2 V c. 8 V
b. 4 V d. 16 V
108. * An electron is circulating in a circular path with a frequency of 50 Hz. What is associated
current?
a. 0.8 × 10-17 A c. 0.4 × 10-17 A
b. 8 × 10-17 A d. 80 × 10-17 A
109. * 4 cells, each of EMF 2V and internal resistance of 1 ohm are connected in parallel to a load
resistor of 2 ohm. Then, the current through the load resistor is:
a. 2.0 A c. 1.0 A
b. 1.5 A d. 0.89 A
110. Total number of electrons present in 4 amp current flowing for 1 sec is:
a. 2.5 × 1019 c. 1.25 × 1013
b. 2.5 × 1020 d. 6 × 108
111. Calculate current I in the adjoining circuit.

a. 0.1 amp c. 0.4 amp

b. 0.2 amp d. 0.3 amp
112. * A block has dimensions 1 cm, 2 cm and 3 cm. Ratio of the maximum resistance to minimum
resistance between any opposite forces of this block is:

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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
a. 9 : 1 c. 18 : 1
b. 1 : 9 d. 1 : 6
113. Two cells having EMF 4V and 2V and internal resistance 1 𝛀 and 1 𝛀 are connected as shown
in the figure. Current through 6 𝛀 resistance is:

a. (1/3) A c. (2/6) A
b. (2/3) A d. (2/9) A
114. Two copper wires of length L and 2L have radii, r and 2r respectively. What is the ratio of
their specific resistances?
a. 1 : 2 c. 1 : 1
b. 2 : 1 d. 1 : 3
115. * Resistance of rod is 1 𝛀. It is bent in the form of square. What is the resistance across
adjoint corners?
a. 1Ω c. (3/16)Ω
b. 3Ω d. (3/4)Ω
116. In the given circuit, the voltmeter records 5V. The resistance of the voltmeter (in ohm) is:
(Please note that key in the given circuit is closed)

a. 200 c. 10
b. 100 d. 50
117. Metals have:
a. Zero resistivity c. Low resistivity
b. High resistivity d. Infinite resistivity
118. Which of the following materials is the best conductor of electricity?
a. Platinum c. Silicon
b. Gold d. Copper
119. At room temperature copper has free electron density of 8.4 × 1028 m-3. The electron drift
velocity in a copper conductor of cross sectional area of 10-6 m2 and carrying a current of
5.4 A, will be:
a. 4 m/s c. 4 cm/s
b. 0.4 m/s d. 0.4 mm/s
120. In the electrical network shown in the figure, the potential difference across 3𝛀 resistance
will be:

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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A

a. 12 V c. 24 V
b. 2.4 V d. 36 V
121. If the electric current through an electric bulb is 3.2 A, the number of electrons flowing
through it in 1 second is:
a. 2 × 109 c. 3.2 × 1019
b. 2 × 1019 d. 1.6 × 1018
122. A wire (P) has resistance of 20 ohm. Another wire (Q) of same material but length twice
that of P has resistance of 8 ohm. If r is the radius of cross section of P, the radius of cross
section of Q is:
a. r c. r √5
b. r/√2 d. 2r
123. The resistance of a wire at room temperature 30℃ is found to be 10 𝛀. Now to increase the
resistance by 10%, the temperature of the wire must be:
(The temperature coefficient of resistance of the material of wire is 0.002/℃)
a. 36℃ c. 63℃
b. 83℃ d. 33℃
124. A current of 5A is passing through a metallic wire of cross sectional area 4 × 10-6 m2. If the
density of charge carriers of the wire is 5 × 1026 m-3, the drift velocity of the electrons will
be:
a. 1 × 102 m/s c. 1.56 × 10-3 m/s
b. 1.56 × 10-2 m/s d. 1.56 × 10-2 m/s
125. The resistance of a wire is 5 ohm at 50℃ and 6 ohm at 100℃. The resistance of the wire at
0℃ will be:
a. 3 ohm c. 1 ohm
b. 2 ohm d. 4 ohm
126. * An aluminum rod and a copper rod are taken such that their lengths are same and their
resistances are also same. The specific resistance of copper is half that of aluminum, but its
density is three times that of aluminum. The ratio of the mass of aluminum rod and that of
copper rod will be:
a. 1/6 c. 1/3
b. 2/3 d. 6
127. Two wires (P) and (Q) made up of different materials have same resistances at room
temperature. When heated, resistance of P increases while that of Q decreases. We
conclude that:
a. P and Q both are conductors but because of being made of different materials it happens so
b. P is N-type semiconductor and Q is P-type semiconductor
c. P is semiconductor and Q is conductor
d. P is conductor and Q is semiconductor

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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
128. The equivalent resistances between A and B (of the circuit shown) is:

a. 4.5 Ω c. 5.4 Ω
b. 1.2 Ω d. 2.0 Ω
129. * The currents I1 and I2 through the resistors R1 (10 𝛀) and R2 (30 𝛀) in the circuit diagram
with E1 = 3V, E2 = 3V and E3 = 2V respectively (Kirchhoff’s Law Application):

a. 0.2 A, 0.1 A c. 0.1 A, 0.2 A

b. 0.4 A, 0.2 A d. 0.2 A, 0.1 A
130. When a battery is connected across a resistor of 16 𝛀, the voltage across the resistor is 12
V. When the same battery is connected across a resistor of 10 𝛀, voltage across it is 11 V.
The internal resistance of the battery (in ohm) is:
a. 10/7 c. 25/7
b. 20/7 d. 30/7
131. Two wires have lengths, diameters and specific resistances all in the ratio of 1 : 2. The
resistance of the first wire is 10 ohm. Resistance of the second wire (in ohm) will be:
a. 5 c. 20
b. 10 d. Infinite
132. * In the given circuit, the current through the 4 𝛀 resistor is 1 amp when the point P and M
are connected to a DC voltage source. The potential difference between the points M and N
is:

a. 0.5 volt c. 1.5 volt

b. 3.2 volt d. 1.0 volt
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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
133. The internal resistance of a cell of EMF (4V) is 0.1 𝛀. It is connected to a resistance of 3.9 𝛀.
The voltage across the cell will be:
a. 3.9 V c. 0.1 V
b. 2.0 V d. 3.8 V
134. Cross sectional area of a copper wire is equal to area of a square of length 2 mm. If this
copper wire draws 8 A electric current, then find the drift velocity of free electrons.
(Number of density in copper wire is 8 × 1028/m3)
a. 3.12 × 10-3 m/s c. 1.56 × 10-4 m/s
b. 3.12 × 10-2 m/s d. 1.56 × 10-2 m/s
135. * Two copper wires have their masses in the ratio 2 : 3 and the lengths in the ratio 3 : 4. The
ratio of their resistances is:
a. 4 : 9 c. 16 : 9
b. 27 : 32 d. 27 : 28
136. A small power station supplies electricity to 5000 lamps connected in parallel. Each lamp
has a resistance of 220 𝛀 and is operated at 220 V. The total current supplied by the station
is:
a. 2500 A c. 5000 A
b. 3500 A d. 10000 A
137. The current in a circuit containing a battery connected to 2 𝛀 resistance is 0.9 A. When a
resistance of 7 𝛀 is connected to same battery, the current observed in the circuit is 0.3 A.
Then the internal resistance of the battery is:
a. 0.1 Ω c. 1 Ω
b. 0.5 Ω d. Zero
138. Consider a rectangular slab of length L and area of cross section A. A current I is passed
through it. If the length is doubled, the potential drop across the end faces:
a. Becomes half of the initial value
b. Becomes one fourth of the initial value
c. Becomes double the initial value
d. Remains same
139. * An aluminum (Al) rod with area of cross section 4 × 10-6 m2, has a current of 5A, flowing
through it. Find the drift velocity of electron in the rod. Density of Al = 2.7 × 103 Kg/m3 and
atomic weight = 27. Assume that each Al atom provides one electron.
a. 8.6 × 10-4 m/s c. 2.8 × 10-2 m/s
b. 6.2 × 10-4 m/s d. 0.12 × 10-3 m/s
140. Six resistors, each of value 3𝛀 are connected as shown in the adjoining figure. A cell of EMF
3 volt is connected across AB. The effective resistance across AB and the current through
the arm AB will be:

a. 0.6 Ω, 1 A c. 0.6 Ω, 2 A
b. 1.5 Ω, 2 A d. 1.5 Ω, 1 A
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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
141. * A wire of resistance 12 ohm/meter is bent to form a complete circle of radius 10 cm. The
resistance between its two diametrically opposite points A and B as shown in the figure is:

a. 3 Ω c. 6 Ω
b. 6 π Ω d. 0.6 π Ω
142. In the adjoining shown circuit, a voltmeter of resistance R, when connected across B and C
𝟏𝟎𝟎
reads V. Neglecting the internal resistance of the battery, the value of R is:
𝟑

a. 100 KΩ c. 50 KΩ
b. 75 KΩ d. 25 KΩ
143. * The reading of the ammeter in the adjoining figure will be:

a. 0.8 A c. 0.4 A
b. 0.6 A d. 0.2 A
144. * The equivalent resistance between points A and B with switch S open and closed are
respectively:

a. 4 Ω, 8 Ω c. 6 Ω, 9 Ω
b. 8 Ω, 4 Ω d. 9 Ω, 6 Ω

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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
145. * In the adjoining circuit, the current through 8 ohm is same before and after connecting E.
The value of E is:

a. 12 V c. 4 V
b. 6 V d. 2 V
146. By increasing the temperature, the conductance of a conductor and a semiconductor.
a. Increases for both c. Increases, decreases
b. Decreases for both d. Decreases, increases
147. The potential difference in open circuit for a cell is 2.2 V. When a 4 𝛀 resistor is connected
between two electrodes, the potential difference becomes 2V. The internal resistance of the
cell will be:
a. 1 Ω c. 2.5 Ω
b. 0.2 Ω d. 0.4 Ω
148. A nichrome wire 50 cm long and 1mm cross section carries a current of 4A when connected
2

to a 2V battery. The resistivity of nichrome wire is:

a. 1 × 106 Ω-m c. 3 × 10-7 Ω-m
b. 4 × 10-7 Ω-m d. 2 × 10-7 Ω-m
149. A wire of length (L) is drawn (stretched) such that its diameter (d) is reduced to half of its
original diameter. If the initial resistance of the wire was 10 𝛀, its new resistance would be:
a. 40 Ω c. 120 Ω
b. 80 Ω d. 160 Ω
150. An electron moving in a circular path of radius 0.5 m with a period of 10 -19 s. The current
constituted in the circular path is:
a. 0.1 A c. 1.9 A
b. 2.5 A d. 1.6 A
151. In a circuit shown in the following figure:

The current through:

a. The 3 Ω resistor is 0.50 A c. The 4 Ω resistor is 0.50 A
b. The 3 Ω resistor is 0.25 A d. The 4 Ω resistor is 0.25 A
152. Find the TRUE statement.
a. Ohm’s law is applicable to all conductors of electricity.
b. In an electrolyte solution, the electric current is mainly due to movement of electrons.
c. The resistance of an incandescent lamp is lesser when the lamp is switched on.
d. Specific resistance of a wire depends upon its dimensions.
e. The resistance of carbon decreases with the increase of temperature.
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 CHAPTER # 13: CURRENT ELECTRICITY: PRACTICE SHEET # 13 - A
153. The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of
10 𝛀 is:
a. 0.5 Ω c. 1.0 Ω
b. 0.8 Ω d. 0.2 Ω
154. When 115 V Potential Difference is applied across a wire that is 10 m long and has a current
density equal to 1.4 × 104 A/m2. The resistivity of the wire is:
a. 2.0 × 10-4 Ωm c. 8.2 × 10-4 Ωm
b. 4.1 × 10 Ωm
-4 d. 2.0 × 10-3 Ωm
155. A uniform wire of resistance 9𝛀 is joined end to end to form a circle. Then the resistance of
the circular wire between any two diametrically opposite points is:
a. 6Ω c. 9/4 Ω
b. 3Ω d. 3/2 Ω
156. The resistance of a wire is R ohm. It is melted and stretched to n times its original length,
its new resistance will be:
R R
a. n c. n2
b. n2R d. nR

P.S: All Questions That Are Marked With (*) Are Placed To Clear The Concepts. You Can
Ignore Them (If You Want To) As They Will Never Come In An Aptitude Exam.

For learning the concepts regarding Current Electricity, you are advised to watch
Lecture # 01 – 04 (in case you have missed class lectures):
YouTube Physics by Bilal Zia Playlist Crash Revision XII Lect. 1-4

“Success In Exams Is Directly Proportional To Hard Work, Dedication, Class

Room Notes Preparation & Attention You Pay During The Lecture While Your
DHEETPAN Remain Constant”

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