NEET Current Electricity PYQs with Solutions | 2013–2025

Chapterwise NEET Questions (2013–2025)

2013

1. A wire of uniform cross-section and length L has resistance R. If the wire is stretched to double its length without changing the volume, calculate the new resistance.
2. Three resistors of 4 Ω, 6 Ω, and 12 Ω are connected in parallel across a battery. Find the equivalent resistance.
3. In a metallic conductor, electrons move under a potential difference. Derive the expression for drift velocity of electrons.

2014

1. Two resistors $R_1 = 5 Ω$R1​=5Ω and $R_2 = 10 Ω$R2​=10Ω are connected in series with a 12 V battery. Calculate the current in the circuit.
2. A copper wire is 1 m long and has a radius of 1 mm. If the resistivity of copper is $1.68 × 10^{-8} Ωm$1.68×10−8Ωm, find its resistance.
3. Define internal resistance of a cell and explain how it affects terminal voltage when a load is connected.

2015

1. Four resistors, each of 6 Ω, are connected in a square. Find the resistance between two opposite corners.
2. A battery of EMF 12 V and internal resistance 1 Ω is connected to an external resistor of 5 Ω. Find the current and terminal voltage.
3. State Joule’s law of heating and derive an expression for heat produced in a resistor.

2016

1. The current in a wire is 2 A. Find the drift velocity of electrons if the cross-sectional area is $1 mm^2$1mm2 and free electron density is $8.5 × 10^{28} m^{-3}$8.5×1028m−3.
2. A potentiometer wire of length 1.5 m is connected to a 3 V battery. Find the potential gradient.
3. Two resistors 3 Ω and 6 Ω are connected in parallel. If a potential difference of 12 V is applied, find the power dissipated in each resistor.

2017

1. Derive the formula for equivalent resistance of two resistors in parallel.
2. A battery of EMF 9 V and internal resistance 1 Ω is connected to an external resistor. Calculate the external resistance if half of the EMF appears across the external resistor.
3. Explain why resistivity of metals increases with temperature.

2018

1. Two wires of the same material have lengths in the ratio 1:2 and diameters in the ratio 2:1. Find the ratio of their resistances.
2. A circuit contains a 12 V battery and three resistors in series: 2 Ω, 3 Ω, and 5 Ω. Calculate current and voltage drop across each resistor.
3. Define specific resistance. Explain its SI unit.

2019

1. Find the equivalent resistance between points A and B in a combination of resistors (figure-based; describe as necessary for website).
2. A 6 V battery is connected across a resistor of 12 Ω. Find the current and power dissipated.
3. Derive the expression for energy dissipated in a resistor in terms of charge and resistance.

2020

1. A battery of EMF 12 V and internal resistance 2 Ω is connected to a resistor of 10 Ω. Find terminal voltage and current.
2. Derive the formula for current division rule in parallel resistors.
3. Explain the variation of resistance with temperature for a metallic conductor.

2021

1. Three resistors, 4 Ω, 6 Ω, and 12 Ω, are connected in parallel. Find total current drawn from a 12 V supply.
2. A wire of length 2 m and radius 0.5 mm has resistivity $1.68 × 10^{-8} Ω m$1.68×10−8Ωm. Calculate resistance.
3. Explain the principle and working of a potentiometer.

2022

1. A battery of EMF 9 V and internal resistance 1 Ω is connected to an external resistor of 4 Ω. Calculate current, terminal voltage, and power delivered to resistor.
2. Find the resistance of a wire of uniform cross-section, if doubling its length triples its resistance.
3. Derive an expression for drift velocity of electrons in a conductor.

2023

1. Derive Ohm’s law for a metallic conductor using microscopic model.
2. Three resistors are connected in series across a battery. Calculate total current and voltage drop across each resistor.
3. Explain the factors affecting resistivity of a conductor.

2024

1. A 12 V battery of internal resistance 1 Ω is connected to two resistors 4 Ω and 6 Ω in series. Calculate current and voltage across each resistor.
2. Two resistors of 6 Ω and 12 Ω are connected in parallel. Find the current drawn from a 12 V supply.
3. A wire of resistivity $ρ$ρ, length L, and cross-section A is stretched to double its length. Find new resistance.

2025

1. Four identical resistors of 3 Ω each are connected to form a square. Find resistance between opposite corners.
2. A cell of EMF 9 V and internal resistance 1 Ω is connected to a resistor of 8 Ω. Find current, terminal voltage, and power delivered.
3. Explain the difference between series and parallel combination of resistors with formulas.

Answer

Current Electricity – Solutions

2013 – Question 1

Q: A wire of uniform cross-section and length L has resistance R. If the wire is stretched to double its length without changing the volume, calculate the new resistance.

Solution:

1. Resistance of a wire: $R = \rho \frac{L}{A}$R=ρAL​, where $\rho$ρ = resistivity, $L$L = length, $A$A = cross-section area.
2. Volume is constant: $A \cdot L = A’ \cdot L’$A⋅L=A′⋅L′ ⇒ $A’ = \frac{A L}{L’}$A′=L′AL​
   • $L’ = 2L$L′=2L ⇒ $A’ = \frac{A L}{2L} = \frac{A}{2}$A′=2LAL​=2A​
3. New resistance: $R’ = \rho \frac{L’}{A’} = \rho \frac{2L}{A/2} = 4 \frac{\rho L}{A} = 4R$R′=ρA′L′​=ρA/22L​=4AρL​=4R

✅ Answer: $R’ = 4R$R′=4R

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2013 – Question 2

Q: Three resistors of 4 Ω, 6 Ω, and 12 Ω are connected in parallel. Find the equivalent resistance.

Solution:

1. Formula for parallel resistors:

$$\frac{1}{R_{eq}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3}$$Req​1​=R1​1​+R2​1​+R3​1​

2. Substitute values:

$$\frac{1}{R_{eq}} = \frac{1}{4} + \frac{1}{6} + \frac{1}{12} = \frac{3 + 2 + 1}{12} = \frac{6}{12} = \frac{1}{2}$$Req​1​=41​+61​+121​=123+2+1​=126​=21​

3. $R_{eq} = 2 Ω$Req​=2Ω

✅ Answer: $2 Ω$2Ω

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2015 – Question 2

Q: A battery of EMF 12 V and internal resistance 1 Ω is connected to an external resistor of 5 Ω. Find the current and terminal voltage.

Solution:

1. Total resistance: $R_{total} = R_{internal} + R_{external} = 1 + 5 = 6 Ω$Rtotal​=Rinternal​+Rexternal​=1+5=6Ω
2. Current: $I = \frac{EMF}{R_{total}} = \frac{12}{6} = 2 A$I=Rtotal​EMF​=612​=2A
3. Terminal voltage: $V_{terminal} = EMF – I r = 12 – (2 × 1) = 10 V$Vterminal​=EMF−Ir=12−(2×1)=10V

✅ Answer: Current = 2 A, Terminal voltage = 10 V

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2020 – Question 2 (Current Division Rule)

Q: Derive the formula for current division in two parallel resistors.

Solution:

1. Two resistors $R_1$R1​ and $R_2$R2​ in parallel, total current $I$I. Let currents through $R_1$R1​ and $R_2$R2​ be $I_1$I1​ and $I_2$I2​.
2. Voltage across each resistor is same: $V = I_1 R_1 = I_2 R_2$V=I1​R1​=I2​R2​
3. Total current: $I = I_1 + I_2$I=I1​+I2​
4. Express $I_1$I1​ in terms of $I$I:

$$I_1 = \frac{R_2}{R_1 + R_2} I, \quad I_2 = \frac{R_1}{R_1 + R_2} I$$I1​=R1​+R2​R2​​I,I2​=R1​+R2​R1​​I

✅ Answer: $I_1 = \frac{R_2}{R_1+R_2} I, \quad I_2 = \frac{R_1}{R_1+R_2} I$I1​=R1​+R2​R2​​I,I2​=R1​+R2​R1​​I

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2025 – Question 1

Q: Four identical resistors of 3 Ω each are connected to form a square. Find resistance between opposite corners.

Solution:

1. For a square: Two paths from corner to corner: each path has two resistors in series ⇒ 3 + 3 = 6 Ω
2. These two paths are in parallel:

$$R_{eq} = \frac{6 × 6}{6 + 6} = \frac{36}{12} = 3 Ω$$Req​=6+66×6​=1236​=3Ω

✅ Answer: $3 Ω$3Ω

disclaimer:

“Questions are based on past NEET exams and are for educational purposes only.”