For: - 11th, 12th, JEE (Mains + Advance) & NEET

Class : 12th Topic : Current Electricity

1. 1 ampere (A) is equivalent to 8. Which of the following not a unit of electric
a. 1 𝐶 current
b. 1 𝑐𝑜𝑢𝑙𝑜𝑚𝑏- 𝑠𝑒𝑐𝑜𝑛𝑑 a. Ampere-second
𝑐𝑜𝑢𝑙𝑜𝑚𝑏 b. Coulomb/second
c.
𝑠𝑒𝑐𝑜𝑛𝑑
c. Ampere
d. None of these
d. None of these
2. Electric current is
9. The S.I unit of electrical resistance is
a. A vector quantity
a. Weber
b. A scalar quantity
b. Henry
c. Vector and scalar both
c. Tesla
d. None of these
d. None of these
3. Electric current is a
10. 1 ohm is equivalent to
a. Fundamental quantity
a. 1 volt/ampere
b. Derived quantity
b. 1 ampere/volt
c. Both a & b
c. 1 volt-ampere
d. None of these
d. None of these
4. S.I unit of electric current is
11. The S.I unit of electrical Conductance is
a. Coulomb
a. mho
b. Ohm
b. Siemen (S0
c. Ampere
c. Ampere
d. Volt
d. Volt
5. In S.I unit ‘ampere’ is taken as
12. The SI unit of electrical conductivity (𝜎) is
a. Basic unit
a. Siemen/metre
b. Derived unit
b. Siemon
c. Both a & b
c. ohm
d. None of these
d. ohm/metre
6. The strength of an electric current flowing through
a conductor will be 1 A (ampere), if the electric 13. The relation among the electric field (𝐸⃗ ), current
charge passing through any section of the density (𝐽) and resistivity (𝜌) is
conductor in one second is a. 𝐸⃗ = 𝜌𝐽
a. 1 𝐶 b. 𝐽 = 𝜌𝐸⃗
b. 1.6 × 10−19 𝐶
c. 𝜌 = 𝐸⃗ . 𝐽
c. 10 𝐶 d. None of these
1
d. 10
𝐶 14. The SI unit of electrical resistivity (or resistivity or
7. Ampere-hour is a unit of specific resistance) is
a. Power a. 𝑜ℎ𝑚-(𝑚𝑒𝑡𝑟𝑒)2
b. Charge b. 𝑜ℎ𝑚-𝑚𝑒𝑡𝑟𝑒
c. Energy c. 𝑜ℎ𝑚/𝑚𝑒𝑡𝑟𝑒
d. Potential difference d. None of these

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15. When the conductivity of substance becomes 22. Resistance of a wire at 20° 𝐶 is 20 Ω and at
infinite, then the substances are said to have 500° 𝐶 is 60 Ω. At what temperature its resistance
become is 25 Ω.
a. Insulators a. 160° 𝐶
b. Semiconductors b. 250° 𝐶
c. Super conductors c. 100° 𝐶
d. None of these d. 80° 𝐶
16. Two resistors of resistances 𝑅1 and 𝑅2 (where 23. When 5𝑉 potential difference is applied across a
𝑅1 < 𝑅2 ) are connected in series. The effective wire of length 0.1 𝑚, the drift speed of electrons is
resistance is 2.5 × 10−4 𝑚𝑠 −1. If the electron density in the
a. Less than 𝑅1 wire is 8 × 1028 𝑚−3 , the resistivity of the
b. Between 𝑅1 and 𝑅2 material is close to
c. Less than 𝑅2 a. 1.6 × 10−8 Ω𝑚
d. More than 𝑅1 and 𝑅2 b. 1.6 × 10−7 Ω𝑚
17. Two resistors of resistances 𝑅1 and 𝑅2 (where c. 1.6 × 10−6 Ω𝑚
𝑅2 < 𝑅1 ) are connected in parallel. The effective d. 1.6 × 10−5 Ω𝑚
resistance is 24. Across a metallic conductor of non-uniform cross
a. More than 𝑅1 section a constant potential difference is applied.
b. Between 𝑅1 and 𝑅2 The quantity which remains constant along the
c. More than 𝑅2 conductor is
d. Less than 𝑅2 a. Current
18. Electric field (𝐸) and current density (𝐽) has b. Drift velocity
relation c. Electric field
a. 𝐸 ∝ 𝐽−1 d. Current density
b. 𝐸 ∝ 𝐽 25. A material ‘B’ has twice the specific resistance of
1
c. 𝐸 ∝ 𝐽2 ‘A’. A circular wire made of ‘B’ has twice the
1 diameter of a wire made of ‘A’. then for the two
d. 𝐸 ∝ 𝐽 𝐼𝐵
wires to have the same resistance, the ratio 𝐼𝐴
of
19. When the current is flowing through a conductor,
their respective lengths must be
the drift velocity is 𝑣. If 2𝑖 current is flowing
a. 1⁄2
through the same metal but having double the area
b. 1⁄4
of cross-section, then the drift velocity will be
𝑣 c. 2
a. 4
𝑣
d. 1
b. 2 26. Consider a copper wire of length 𝐿, cross-sectional
c. 𝑣 d. 4𝑣 area 𝐴. it has 𝑛 number of free electrons per unit
20. Ohm’s law is valid if volume. Which of the following is the correct
a. 𝑉 is directly proportional to 𝐼 3 expression of drift velocity of the electrons when
b. The relation between 𝑉 and I depends on the wire carries a steady current 𝐼
𝐼
the sign of 𝑉 for the same absolute value a.
𝑛𝑒𝐿
of 𝑉 𝐼
b.
c. 𝑉 is directly proportional to 𝐼 2 𝑛2 𝑒𝐿
𝐼
d. 𝑉 depends on 𝐼 linearly c.
𝑛𝑒𝐴
21. The current flowing through a wire depends on 𝐼
d. 𝑛𝑒 2 𝐿𝐴
time as 𝐼 = 3𝑡 2 + 2𝑡 + 5. The charge flowing
27. Which of the following is a vector quantity
through the cross-section of the wire in time from
a. Current density
𝑡 = 0 to 𝑡 = 2 sec, is
b. Current
a. 22 C
c. Wattless current
b. 20 C
d. Power
c. 18 C d. 5 C

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28. By increasing the temperature, the specific 36. A constant current of 2A passes through a wire for
resistance of a conductor and semiconductor 1 hour. The amount of charge that has flow
a. Increases for both through a cross-sectional area is
b. Decreases for both a. 20 C
c. Increases, decreases b. 2 C
d. Decreases, increases c. 7200 C
29. A wire of certain material is stretched slowly by d. 3600 C
ten percent. Its new resistance and specific 37. The number of electrons flowing per second
resistance become respectively through a cross-section of a conductor for the
a. Both remain the same current to be 1A is
b. 1.1 times, 1.1 times a. 1.6 × 10−19
c. 1.2 times, 1.1 times b. 1.6 × 1019
d. 1.21 times, same c. 6.23 × 1023
30. Drift velocity 𝑣𝑑 varies with the intensity of d. 6.25 × 1018
electric field as per the relation 38. If the electron of hydrogen atom revolves around
a. 𝑣𝑑 ∝ 𝐸 the nucleus 6.25 × 105 times per second, the
1
b. 𝑣𝑑 ∝ current in the orbit is
𝐸
c. 𝑣𝑑 ∝ 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 a. 0.1 𝑚𝐴
d. 𝑣𝑑 ∝ 𝐸 2 b. 1 𝐴
31. The number of different combination made out of c. 10 𝑚𝐴
three equal resistors taken together is d. 1 𝑚𝐴
a. Two 39. A copper wire of diameter 1 mm carries a current
b. Three 6.28 A. The current density in the wire in 𝐴⁄𝑚2 is
c. Four a. 6.28 × 106
d. Six b. 8 × 106
32. The number of different combinations made out of c. 6.28 × 10−6
three unequal resistors taken together is d. 8 × 10−6
a. Two 40. A current of 16A passes through a copper wire of
b. Three cross-sectional area 1𝑚𝑚2 containing 1029 free
c. Six electron per cubic meter. The drift speed of the
d. Eight electron is
33. The number of different combinations made out of a. 1 𝑚⁄𝑠
three identical resistors taking two identical and b. 0.1 𝑚𝑚⁄𝑠
one different resistance taken is c. 1 𝑚𝑚⁄𝑠
a. Three d. 1.6 × 10−3 𝑚⁄𝑠
b. Four 41. The tolerance level of a resistor with the colour
c. Six code red, blue, orange, gold is
d. Seven a. ±5%
34. The SI unit of electrical power is b. ±10%
a. Volt c. ±20%
b. Watt d. ±25%
c. Ampere 42. The colour sequence in a carbon resistor is red,
d. Ohm brown, orange and silver. The resistance of the
35. Which of the following units is not equal to 1 watt resistor is
(W)? a. 21 × 103 ± 10%
b. 23 × 103 ± 10%
a. 𝑣𝑜𝑙𝑡-𝑎𝑚𝑝𝑒𝑟𝑒
c. 21 × 103 ± 5%
b. (𝑣𝑜𝑙𝑡)2 ⁄𝑜ℎ𝑚
d. 12 × 103 ± 5%
c. (𝑎𝑚𝑝𝑒𝑟𝑒)2⁄𝑜ℎ𝑚
d. 𝑣𝑜𝑙𝑡⁄𝑎𝑚𝑝𝑒𝑟𝑒

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43. The colour code for a resistor of resistance 3.5𝑘Ω 50. Two resistors R and 2R are connected in series in
with 5% tolerance is an electric circuit. The thermal energy developed
a. Orange, green, red and gold in R and 2R are in the ratio
b. Red, yellow, black and gold a. 1 : 2
c. Orange, green, orange and silver b. 2 : 1
d. Orange, green, red and silver c. 1 : 4
44. A carbon resistor (47 ± 4.7) 𝑘Ω is to be marked d. 4 : 1
with rings of different colours for its identification. 51. Two resistances R and 2R are connected in
The colour code sequence will be
parallel in an electric circuit. The thermal energy
a. Violet-Yellow-Orange-Silver
developed in R and 2R are in the ratio
b. Yellow-Violet-Orange-Silver
c. Yellow-Green-Violet-Gold a. 1 : 2
d. Green-Orange-Violet-Gold b. 2 : 1
45. In the figure a carbon resistor has band of different c. 1 : 4
colours on its body as mentioned in the figure. The d. 4 : 1
value of the resistance is 52. A uniform wire of resistance 50 Ω is cut into 5
equal parts. These parts are now connected in
a. 2.2 𝑘Ω parallel. The equivalent resistance of the
b. 3.3 𝑘Ω combination is
c. 5.6 𝑘Ω a. 2 Ω
d. 9.1 𝑘Ω b. 10 Ω
46. Two resistors A and B have resistance 𝑅𝐴 and 𝑅𝐵 c. 250 Ω
respectively with 𝑅𝐴 < 𝑅𝐵 . The resistivity of their d. 6250 Ω
materials are 𝜌𝐴 and 𝜌𝐵 . 53. Consider the following statements: (A)
a. 𝜌𝐴 > 𝜌𝐵 Kirchhoff’s junction law follows conservation of
b. 𝜌𝐴 = 𝜌𝐵 charge. (B) Kirchhoff’s loop law follows from
c. 𝜌𝐴 < 𝜌𝐵 conservative nature of electric field.
d. The information is not sufficient to find a. Both A and B are correct
the relation between 𝜌𝐴 and 𝜌𝐵 b. A is correct but B is wrong
47. The product of resistivity and conductivity of a c. B is correct but A is wrong
cylindrical conductor depends on d. Both A and B are wrong
a. Temperature 54. 1 kilowatt hour is commonly known as
b. Material a. 1 unit
c. Area of cross-section b. 1 faraday
d. None of these c. 1 curie
48. As the temperature of a metallic resistor is d. None of these
increased, the product of its resistivity and 55. The resistivity of a conductor depends upon its
conductivity a. Length
a. Increases b. Area of cross-section
b. Decreases c. Resistance
c. Remains constant d. None of these
d. May increase or decrease
49. A resistor of resistance R is connected to an ideal
battery. If the value of R is decreased, the power
…………………The End………………………….
dissipated in the resistor will be
a. Increases
b. Decreases
c. Remain unchanged
d. May increase or decrease

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