Current Electricity NEET Questions with Solutions

Q: How many questions come from Current Electricity in NEET 2027?

You can expect 2 questions from this chapter in NEET 2027. The chapter has the highest PYQ frequency in Physics. Resistor combinations, Kirchhoff's laws, Wheatstone bridge, EMF with internal resistance and electrical power are repeated every year.

Q: What is Ohm's law?

For most metallic conductors at constant temperature, the current I through a conductor is directly proportional to the potential difference V across it. The constant of proportionality is called resistance: V equals I R. Materials that follow this law are called ohmic; semiconductors, gases and vacuum tubes are non-ohmic.

Q: What is drift velocity?

Free electrons in a metal move randomly at high speeds (about 10 to the 5 m per s). When you apply a field, they pick up a tiny additional drift velocity (about a millimetre per second) in the direction opposite to the field. The current is I equals n A e v_d, where n is the number of free electrons per cubic metre, A is cross-section, e is electron charge.

Q: How do resistors combine in series and parallel?

Series: same current through each, voltages add. R_eff equals R_1 plus R_2 plus R_3. Parallel: same voltage across each, currents add. 1 over R_eff equals 1 over R_1 plus 1 over R_2 plus 1 over R_3. Series gives larger total R; parallel gives smaller R, less than the smallest.

Q: What are Kirchhoff's laws?

Two rules for solving circuits. KCL (junction rule): the sum of currents flowing into any junction equals the sum flowing out. This is conservation of charge. KVL (loop rule): the algebraic sum of voltage changes around any closed loop is zero. This is conservation of energy.

Q: What is the Wheatstone bridge balance condition?

A Wheatstone bridge has four resistors P, Q, R and S arranged in a diamond, with a galvanometer between the two midpoints. The bridge is balanced (no current through the galvanometer) when P over Q equals R over S. NEET often gives three of the four resistors and asks for the fourth.

Q: What is the difference between EMF and terminal voltage?

EMF (epsilon) is the voltage of a cell when no current flows: the maximum voltage it can provide. When the cell drives current I through external resistance R, internal resistance r drops some voltage. Terminal voltage V equals epsilon minus I r. So when current flows, V is less than epsilon. When the cell is being charged, V is greater than epsilon.

Question 1

A 12 V battery drives a current of 2 A through a resistor. The resistance is:

Accepted Answer

6 Ω

Question 2

Three resistors of 4 Ω each in parallel give:

Accepted Answer

4/3 Ω

Question 3

A 100 W bulb on 220 V has resistance:

Accepted Answer

484 Ω

Question 4

Wheatstone bridge balance condition:

Accepted Answer

[math]

Question 5

A cell of EMF 6 V and internal resistance 1 Ω is connected to a 5 Ω external resistor. The current is:

Accepted Answer

1 A

Question 6

A wire of resistance R is stretched to twice its length. The new resistance is:

Accepted Answer

4R

Question 7

Kirchhoff's loop rule (KVL) is a statement of:

Accepted Answer

Energy conservation

Question 8

Two resistors of 4 Ω and 6 Ω are connected in series. Equivalent:

Accepted Answer

10 Ω

Question 9

Two bulbs rated 60 W and 100 W are connected in series across 220 V. Which glows brighter?

Accepted Answer

60 W bulb

Question 10

Drift velocity of electrons in a wire is given by:

Accepted Answer

[math]

Question 11

Terminal voltage of a cell during charging:

Accepted Answer

Greater than EMF

Question 12

At a junction, currents 3 A and 5 A flow in. Currents 2 A and X flow out. X equals:

Accepted Answer

6 A

Question 13

SI unit of resistivity is:

Accepted Answer

Ω·m

Question 14

In a balanced Wheatstone bridge, the galvanometer current is:

Accepted Answer

Zero

Question 15

Two resistors R₁ and R₂ in parallel give effective R. If R₁ = R₂ = R, then effective R is:

Accepted Answer

[math]

Question 16

A heater consumes 2000 W on 220 V. The current through it is:

Accepted Answer

9 A

Question 17

A cell delivers maximum power to an external load when:

Accepted Answer

[math]

Question 18

In a closed loop with EMFs and resistors, the algebraic sum of EMFs equals:

Accepted Answer

Sum of IR drops

Question 19

In a meter bridge, the balance point is at 40 cm from one end. The ratio of the two resistors P and Q (where P is on the side of l = 0 to 40):

Accepted Answer

2:3

Question 20

Voltage across a 5 Ω resistor with 0.4 A is:

Accepted Answer

2 V

Question 21

A wire of resistance R is cut into 5 equal parts and joined in parallel. Resistance of the combination is:

Accepted Answer

[math]

Question 22

If voltage across a wire is doubled, drift velocity:

Accepted Answer

Doubles

Question 23

Energy used by a 60 W bulb in 5 hours:

Accepted Answer

0.3 kWh

Question 24

Two cells of EMF 6 V and 4 V (with negligible internal resistances) are connected in opposite polarities (so they oppose). The effective EMF is:

Accepted Answer

2 V

Question 25

Temperature coefficient of resistance for a metal is:

Accepted Answer

Positive

Question 26

In a Wheatstone bridge, P = 100 Ω, Q = 200 Ω, R = 50 Ω. For balance, S equals:

Accepted Answer

100 Ω

Question 27

Two 100 W bulbs in parallel across a 220 V supply consume total power:

Accepted Answer

200 W

Question 28

Three identical resistors R are connected in a triangle. Resistance between any two corners is:

Accepted Answer

[math]

Question 29

Kirchhoff's junction rule (KCL) is a statement of:

Accepted Answer

Charge conservation

Question 30

Internal resistance of a cell is determined from the slope of:

Accepted Answer

V vs I curve

Question 31

A resistor at 20 °C has 100 Ω. At 120 °C (with α = 0.004/K), its resistance is:

Accepted Answer

140 Ω

Question 32

Typical drift speed of electrons in a copper wire carrying ordinary current is:

Accepted Answer

[math] m/s

Current ElectricityNEET Physics · Class 12 · NCERT Chapter 3

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Current ElectricityNEET Physics · Class 12 · NCERT Chapter 3

1NEET 2018EasyA 12 V battery drives a current of 2 A through a resistor. The resistance is:

2NEET 2020EasyThree resistors of 4 Ω each in parallel give:

3NEET 2022MediumA 100 W bulb on 220 V has resistance:

4NEET 2024MediumWheatstone bridge balance condition:

5NEET 2017MediumA cell of EMF 6 V and internal resistance 1 Ω is connected to a 5 Ω external resistor. The current is:

6NEET 2019MediumA wire of resistance R is stretched to twice its length. The new resistance is:

7NEET 2021MediumKirchhoff's loop rule (KVL) is a statement of:

8NEET 2023MediumTwo resistors of 4 Ω and 6 Ω are connected in series. Equivalent:

9NEET 2018MediumTwo bulbs rated 60 W and 100 W are connected in series across 220 V. Which glows brighter?

10NEET 2020MediumDrift velocity of electrons in a wire is given by:

11NEET 2022MediumTerminal voltage of a cell during charging:

12NEET 2024MediumAt a junction, currents 3 A and 5 A flow in. Currents 2 A and X flow out. X equals:

13NEET 2017EasySI unit of resistivity is:

14NEET 2019MediumIn a balanced Wheatstone bridge, the galvanometer current is:

15NEET 2021MediumTwo resistors R₁ and R₂ in parallel give effective R. If R₁ = R₂ = R, then effective R is:

16NEET 2023MediumA heater consumes 2000 W on 220 V. The current through it is:

17NEET 2018MediumA cell delivers maximum power to an external load when:

18NEET 2020MediumIn a closed loop with EMFs and resistors, the algebraic sum of EMFs equals:

19NEET 2022MediumIn a meter bridge, the balance point is at 40 cm from one end. The ratio of the two resistors P and Q (where P is on the side of l = 0 to 40):

20NEET 2024EasyVoltage across a 5 Ω resistor with 0.4 A is:

21NEET 2017MediumA wire of resistance R is cut into 5 equal parts and joined in parallel. Resistance of the combination is:

22NEET 2019MediumIf voltage across a wire is doubled, drift velocity:

23NEET 2021MediumEnergy used by a 60 W bulb in 5 hours:

24NEET 2023MediumTwo cells of EMF 6 V and 4 V (with negligible internal resistances) are connected in opposite polarities (so they oppose). The effective EMF is:

25NEET 2018MediumTemperature coefficient of resistance for a metal is:

26NEET 2020MediumIn a Wheatstone bridge, P = 100 Ω, Q = 200 Ω, R = 50 Ω. For balance, S equals:

27NEET 2022MediumTwo 100 W bulbs in parallel across a 220 V supply consume total power:

28NEET 2024MediumThree identical resistors R are connected in a triangle. Resistance between any two corners is:

29NEET 2017MediumKirchhoff's junction rule (KCL) is a statement of:

30NEET 2019MediumInternal resistance of a cell is determined from the slope of:

31NEET 2021MediumA resistor at 20 °C has 100 Ω. At 120 °C (with α = 0.004/K), its resistance is:

32NEET 2023MediumTypical drift speed of electrons in a copper wire carrying ordinary current is:

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