# CBSE Class 12 Physics Chapter 3 Current Electricity MCQs

CBSE Class 12 Physics Chapter 3 Current Electricity MCQs. These MCQs of Current Electricity chapter are prepared by our Physics Expert. By practising following MCQs, students will be able to quickly revise all the concepts of the chapter.

Additionally, these MCQs of Current Electricity will be helpfull for JEE And NEET Aspirants. These MCQs on Current Electricity chapter are prepared as per the latest curriculum issued by the CBSE.

### CBSE Class 12 Physics Chapter 3 Current Electricity MCQs

1. The new resistance of the wire
will be if the resistance of a wire is 20 𝑜ℎ𝑚. If length becomes three times by stretching
(a) 6.67 ohms
(b) 60.0 ohms
(c) 120 ohms
(d) 180.0 ohms

2. What will be Resistance if the length and area of crosssection both are doubled.
(a) Will become half
(b) Will remain the same
(c) Will be doubled
(d) Will become four times
Answer: Will remain the same

3. Current of 4.8 amperes is flowing
through a conductor. The number of
electrons per second will be
(a) 3 × 10^19
(b) 7.68 × 10^21
(c) 7.68 × 10^20
(d) 3 × 10^20
Answer: 3 × 10^19

4. If a 0.1 % increase in length due to
stretching, the percentage increase in its
resistance will be
(a) 0.2 %
(b) 2 %
(c) 1 %
(d) 0.1 %

5. As the temperature of a metallic
resistor is increased, the product of
resistivity and conductivity :-
(a) increases
(b) decreases
(c) may increase or decrease
(d) remains constant

6. At what temperature will the
resistance of a copper wire become three
times its value at 0°𝐶?
(a) 400° C
(b) 450° C
(c) 500° C
(d) 600° C

7. The resistance of a conductor is
5 𝑜ℎ𝑚 at 50 °𝐶 and 6 𝑜ℎ𝑚 at 100 °𝐶 Its
resistance at 0 °𝐶 is
(a) 1 ohm
(b) 2 ohm
(c) 3 ohm
(d) 4 ohm

8. The conductivity of a superconductor
is
(a) Infinite
(b) Very large
(c) Very small
(d) Zero

9. Five cells each of internal resistance
0.2Ω and e.m.f. 2𝑉 are connected in series
with a resistance of 4 Ω. The current
through the external resistance is
(a) 0.2 𝐴
(b) 0.5 𝐴
(c) 1 𝐴
(d) 2 𝐴

10. Internal resistance of primary cell
depends on :-
(a) the nature of electrolyte
(b) the area of plates immersed in the
electrolyte
(c) the concentration of electrolyte and
distance between the plates
(d) all the above
Answer: all the above

11. In a Wheatstone’s network, 𝑃 = 2 Ω,
𝑄 = 2 Ω, 𝑅 = 2 Ω and 𝑆 = 3 Ω. The
resistance with which 𝑆 is to be shunted in
order that the bridge may be balanced is
(a) 1 Ω
(b) 2 Ω
(c) 4 Ω
(d) 6 Ω

12. The terminal voltage is 𝐸/2 when a
current of 2 𝐴 is flowing through 2 Ω
resistance; the internal resistance of the
cell is :–
(a) 1 Ω
(b) 2 Ω
(c) 3 Ω
(d) 4 Ω

13. In a Wheatstone bridge if the battery
and galvanometer are interchanged then
the deflection in galvanometer will
(a) change in previous direction
(b) not change
(c) change in opposite direction
(d) none of these.

14.Three resistance of values 2Ω, 3Ω
and 6Ω are to be connected to yield and
effective resistance of 4Ω. This can be
done by connecting:
(a) 3Ω resistance in series with a
parallel combination of 2Ω and 6Ω
(b) 6Ω resistance in series with a
parallel combination of 2Ω and 3Ω
(c) 2Ω resistance in series with a
parallel combination of 3Ω and 6Ω
(d) 2Ω resistance in parallel with a
parallel combination of 3Ω and 6Ω
Answer: 2Ω resistance in series with a
parallel combination of 3Ω and 6Ω

15. 62.5 ×10^18 electrons per second are flowing through a
wire of area of cross-section 0.1 m2, the value of
current flowing will be _____.
(a) 1 A
(b) 0.1 A
(c) 10 A
(d) 0.11 A

16. A steady current flows in a metallic conductor of nonuniform cross-section. The quantity/ quantities
constant along the length of the conductor is/are _____.
(a) Current, electric field and drift speed
(b) Drift speed only
(c) Current and drift speed
(d) Current only

17. The relaxation time in conductors _____.
(a) Increases with the increase of temperature
(b) Decreases with the increase of temperature
(c) It does not depend on temperature
(d)none
Answer: Increases with the increase of temperature

18. A potential difference of V is applied at the ends of a
copper wire of length and diameter. On doubling only
d, drift velocity _____.
(a) Becomes two times
(b) Becomes half
(c) Does not change
(d) Becomes one fourth
Answer: Does not change

19. If three resistance, 2Ω, 3Ω & 4Ω are connected in
parallel, then equivalent resistance is
(a) < 2Ω
(b) ≤ 2Ω
(c) > 2Ω
(d) ≥ 2Ω

20. Which one of the following does not follow ohm’s law.
(a) Diode
(b) Transistor
(c) Thyristor
(d) All of these
Answer: All of these

21. A storage battery has e.m.f. 15 volts and internal resistance 0.05 ohm. Its terminal voltage when it is delivering 10 ampere is _____.
(a) 30 volts
(b) 1.00 volts
(c) 14.5 volts
(d) 15.5 volts

22. Then resistance in right and left gap of a meter bridge
is 20cm and 50cm respectively. If they are interchanged
then shift in position of balance point is
(a)22.84 cm
(b) 32.68 cm
(C) 42.86 cm
(d) 52.18 cm

23. Principle of working of meter-bridge is
(a) Unbalanced wheat stone bridge
(b) Balanced wheat stone bridge
(c) Potential drop is directing proportional length
(d) Both (b) & (c)
Answer: Unbalanced wheat stone bridge

24. Accuracy of metre-bridge is maximum when null
point is obtained
(a) In between 30cm – 70 cm
(b) In between 40cm – 60 cm
(c) In between 45cm – 55 cm
(d) Accuracy is same is all cases
Answer: Accuracy is same is all cases

25. Sensitivity of potentiometer can be increased by
(a) Increasing length of potentiometer wire
(b) Decreasing length of potentiometer wire
(c) Increasing emf of driver cell
(d) Both (1) &(2)
Answer: Decreasing length of potentiometer wire

26. A 4V ideal battery is
connected across a uniform wire
of length 10m. Two points on this wire, separated by
120 cm. The potential difference between these two points, is
(a) 6/25V
(b) 1/25V
(c) 9/25V
(d) None