NEET PhysicsUpdated 19 Oct 2026

Current Electricity: NEET PYQs and weightage

Current Electricity carries 7.1 of 100 Physics marks in NEET by past-paper share: 54 of the 758 tagged NEET Physics PYQs in the ViJEEta bank (NEET 2013–2026). It ranks 1 of 30 Physics chapters.

Take the 25-question Current Electricity test Formula sheet ↓All NEET Physics chapters

7.1/100 Weight in Physics

Exam importance (5/5, by past-paper share)

54 NEET PYQs

450 Practice questions

431 With measured difficulty

How the weight is computed: this chapter's tagged NEET PYQs divided by all tagged NEET Physics PYQs in the bank (54 of 758), times 100, with repeated questions counted once. The bank does not store the year of each NEET question, so none is printed. Computed from the bank at build time. Updated 19 Oct 2026.

Current Electricity: formula sheet for NEET

14 formulas, each with when to use it. Copy it onto one page of your notebook: that page is this chapter's handbook.

Ohm's law
$V = I R$
Use it when: you know any two of voltage, current and resistance for a resistor
Resistance of a wire
$R = \frac{ρl}{A}$
Use it when: a wire is stretched, cut or swapped for one of another length, thickness or material
Terminal voltage of a cell
$V = ε - I r (cell supplying current)$
$V = ε + I r (current forced into the cell from + to -, as in charging)$
Use it when: a question asks for the voltage across a real cell's terminals
Current from a cell
$I = \frac{ε}{R + r}$
$I_{m a x} = \frac{ε}{r} (short circuit, R = 0)$
Use it when: one cell with internal resistance $r$ drives an external resistance $R$
Power in a resistor
$P = V I = I^{2} R = \frac{V ^{2}}{R}$
Use it when: you need heat or power. Use $I^{2} R$ when current is fixed (series) and $V^{2} / R$ when voltage is fixed (parallel)
Current from drift
$I = n e A v_{d}$
Use it when: a question gives the free-electron density $n$ and asks for drift speed (typically a fraction of a mm/s to a few mm/s)
Drift velocity
$v_{d} = \frac{e E τ}{m} (directed opposite to E)$
Use it when: the field or the relaxation time $τ$ is given
Resistivity from the electron model
$ρ = \frac{m}{n e ^{2} τ}$
$σ = \frac{1}{ρ} = \frac{n e ^{2} τ}{m}$
Use it when: you need to explain why $ρ$ rises with temperature in metals ( $τ$ falls) and falls in semiconductors ( $n$ rises)
Current density
$j = \frac{I}{A}$
$j = σ E (equivalently E = ρ j)$
$unit A/ m^{2}$
Use it when: a field inside the wire or a current per unit area is asked
Mobility
$μ = \frac{v _{d}}{E} = \frac{e τ}{m}$
$unit m^{2} / (V \cdot s)$
Use it when: mobility is given instead of $τ$
Temperature dependence
$ρ_{T} = ρ_{0} [1 + α (T - T_{0})]$
$R_{T} = R_{0} [1 + α (T - T_{0})]$
$α in^{\circ} C^{- 1}$
Use it when: a heater or wire warms up and its resistance changes (valid only over a small temperature range)
Cells in series
$ε_{eq} = ε_{1} + ε_{2}$
$r_{eq} = r_{1} + r_{2}$
$ε_{eq} = ε_{1} - ε_{2} (one cell reversed, like terminals joined; ε_{1} > ε_{2})$
$r_{eq} = r_{1} + r_{2} (unchanged)$
Use it when: cells are joined end to end in a single line (one terminal of each joined, the other left free)
Cells in parallel
$\frac{1}{r _{eq}} = \frac{1}{r _{1}} + \frac{1}{r _{2}}$
$\frac{ε _{eq}}{r _{eq}} = \frac{ε _{1}}{r _{1}} + \frac{ε _{2}}{r _{2}}$
$ε_{eq} = \frac{ε _{1} r _{2} + ε _{2} r _{1}}{r _{1} + r _{2}}$
Use it when: the $+$ terminals are joined together and the $-$ terminals are joined together (for one cell reversed, put $- ε_{2}$ )
Kirchhoff and Wheatstone
$\sum I_{in} = \sum I_{out} (at every junction)$
$\sum Δ V = 0 (around every closed loop)$
$\frac{R _{2}}{R _{1}} = \frac{R _{4}}{R _{3}} (bridge balanced, no galvanometer current)$
Use it when: a network won't reduce to simple series or parallel, or a galvanometer reads zero

Trap

Students write V = ε − Ir for every cell. When current is pushed into a cell from its + terminal to its − terminal (charging, or a weaker cell opposed by a stronger one), the terminal voltage is ε + Ir, which is larger than the emf.

How does NEET ask Current Electricity?

8 real previous-year questions from this chapter, as printed in the paper, each with its worked solution. Answer the first one here with no sign-in.

Q1PhysicsNEET UG PYQResistivity of Various Materials

Try right here · No sign-in

As the temperature increases, the electrical resistance:

Answer key (D) & worked solution

Correct answer: Option D

As temperature increases, the resistance increases for conductors, but decreases for semi-conductors.

Q2PhysicsNEET UG PYQOhm's Law

A carbon resistor of

(47 \pm 4.7) k Ω

is to be marked with rings of different colours for its identification. The colour code sequence will be

AYellow – Green – Violet – Gold

BYellow – Violet – Orange – Silver

CViolet – Yellow – Orange – Silver

DGreen – Orange – Violet – Gold

Answer key (B) & worked solution

Correct answer: Option B

(47 \pm 4.7) k Ω = 47 \times 1 0^{3} \pm 10

Yellow – Violet – Orange - Silver

Q3PhysicsNEET UG PYQMiscellaneous Examples

The molar conductance of NaCl. HCl and CH

_{3}

COONa at infinite dilution are 126.45, 426.16 and 91.0 S cm

^{2}

mol

^{- 1}

respectively. The molar conductance of CH

_{3}

COOH at infinite dilution is. Choose the right option for your answer.

A698.28 S cm

^{2}

mol

^{- 1}

B540.48 S cm

^{2}

mol

^{- 1}

C201.28 S cm

^{2}

mol

^{- 1}

D390.71 S cm

^{2}

mol

^{- 1}

Answer key (D) & worked solution

Correct answer: Option D

λ∞(CH

_{3}

COOH) = λ∞(CH

_{3}

COONa) + λ∞(HCl) - λ∞(NaCl) = (91 + 426.16 - 126.45) S cm

^{2}

mol

^{- 1}

= 390.71 S cm

^{2}

mol

^{- 1}

Q4PhysicsNEET UG PYQCells, EMF, Internal Resistance

A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases. The ratio of emfs is

A5 : 1

B5 : 4

C3 : 4

D3 : 2

Answer key (D) & worked solution

Correct answer: Option D

\frac{E _{1} + E _{2}}{E _{1} - E _{2}} = \frac{50}{10} \Rightarrow \frac{2 E _{1}}{2 E _{2}} = \frac{50 + 10}{50 - 10} \Rightarrow \frac{E _{1}}{E _{2}} = \frac{3}{2}

Q5PhysicsNEET UG PYQResistivity of Various Materials

The resistance of platinum wire at

0^{\circ} C

2 Ω

and

6.8 Ω

8 0^{\circ} C

. The temperature coefficient of resistance of the wire is:

3 \times 1 0^{- 3}^{\circ} C^{- 1}

3 \times 1 0^{- 2}^{\circ} C^{- 1}

3 \times 1 0^{- 1}^{\circ} C^{- 1}

3 \times 1 0^{- 4}^{\circ} C^{- 1}

Answer key (B) & worked solution

Correct answer: Option B

R_{T} = R_{0} [1 + α (T - T_{0})]

6.8 = 2 [1 + α (80 - α)]

α = \frac{2.4}{80} = 0.03 /^{\circ} C = 3 \times 1 0^{- 2} /^{\circ} C

Q6PhysicsNEET UG PYQElectrical Energy, Power

The charge flowing through a resistance R varies with time t as Q = at – bt

^{2}

, where a and b are positive constants. The total heat produced in R is

\frac{a ^{3} R}{6 b}

\frac{a ^{3} R}{3 b}

\frac{a ^{3} R}{2 b}

\frac{a ^{3} R}{b}

Answer key (A) & worked solution

Correct answer: Option A

Q = at – at

^{2}

i = a - 2bt (for i = 0 ⇒ t =

\frac{a}{2 b}

) From joule’s law of heating dH = i

^{2}

Rdt

H = 0 \int \frac{a}{2 b} (a - 2 b t)^{2} R d t H = \frac{( a - 2 b t ) ^{3}}{- 3 \times 2 b}_{0}^{\frac{a}{2 b}} = \frac{a ^{3} R}{6 b}

Q7PhysicsNEET UG PYQElectrical Energy, Power

Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall to potential per km is 8 volt and the average resistance per km is 0.5Ω. The power loss in the wire is:

A19.2 J

B12.2 kW

C19.2 W

D19.2 kW

Answer key (D) & worked solution

Correct answer: Option D

P = \frac{V ^{2}}{R} = \frac{( 8 \times 150 ) ^{2}}{0.5 \times 150} = \frac{64 \times 150}{0.5} = 19.2 k W

Q8PhysicsNEET UG PYQKirchhoff's Law & Its Applications

In a potentiometer circuit a cell of EMF 1.5 V gives balance point at 36 cm length of wire. If another cell of EMF 2.5 V replaces the first cell, then at what length of the wire, the balance point occurs?

A64 cm

B62 cm

C60 cm

D21.6 cm

Answer key (C) & worked solution

Correct answer: Option C

Potentiometer

\to

Comparison of EMFs of cells Direct formula:

\frac{E _{1}}{E _{2}} = \frac{ℓ _{1}}{ℓ _{2}}

\frac{1.5 V}{2.5 V} = \frac{36 c m}{ℓ _{2}}

ℓ_{2} = 60 c m

Which topics in Current Electricity carry the most questions?

All 9 topics, by tagged PYQs, then practice questions. Counted from the bank. Updated 19 Oct 2026.

Topic	PYQs	Practice questions
Kirchhoff's Law & Its Applications	15	132
Ohm's Law	11	50
Limitation of Ohm's Law	7	65
Cells, EMF, Internal Resistance	6	55
Resistivity of Various Materials	5	39
Electrical Energy, Power	4	37
Electric Current	2	38
Drift of Electrons	2	30
Miscellaneous Examples	2	4

Why does Current Electricity show "–" until you answer 3 questions?

Unknown is not zero. Until you answer at least 3 graded questions in Current Electricity, ViJEEta shows – instead of a zero or a 50% default. Book exercises can raise chapter mastery up to 0.60, adaptive practice up to 0.75, and only a timed chapter test or mock can certify 0.80 and above.

How ViJEEta scores you

What happens when you test Current Electricity?

Every chapter test is 25 questions. It starts at moderate difficulty and adapts after each saved answer. If you open a solution before answering, that attempt earns no credit, so your mastery stays honest.

Start the Current Electricity test

Chapters either side of Current Electricity by weight

Semiconductor Electronics : Materials, Devices and Simple Circuits Weight 5.5/100 Dual Nature of Radiation and Matter Weight 5.3/100

Current Electricity: NEET PYQs and weightage

Current Electricity: formula sheet for NEET

Ohm's law

Resistance of a wire

Terminal voltage of a cell

Current from a cell

Power in a resistor

Current from drift

Drift velocity

Resistivity from the electron model

Current density

Mobility

Temperature dependence

Cells in series

Cells in parallel

Kirchhoff and Wheatstone

How does NEET ask Current Electricity?

Which topics in Current Electricity carry the most questions?

Why does Current Electricity show "–" until you answer 3 questions?

What happens when you test Current Electricity?

Chapters either side of Current Electricity by weight