JEE (Main) · Physics, Class 12
Electrostatics: JEE Main PYQ, 2020–2025
Electrostatics (Physics, Class 12) has been asked 237 times in the 111 JEE (Main) shift papers from 2020–2025: about 2.1 questions a paper, 8% of all Physics questions. It is the most-asked of 20 Physics chapters. The 2025 shifts had 35 from it in all. Last checked 28 October 2026.
Questions per year, all shifts
Year by year.
| Year | Questions |
|---|---|
| 2020 | 32in 14 papers |
| 2021 | 54in 26 papers |
| 2022 | 53in 24 papers |
| 2023 | 24in 12 papers |
| 2024 | 39in 18 papers |
| 2025 | 35in 17 papers |
JEE (Main) is sat in many shifts a year, each with its own paper; the counts add up every shift. 2021–2024 papers had 30 questions a subject, the others 25.
Inside the chapter
Topics asked most.
- Capacitance81
- Electric field and potential57
- Gauss's law39
- Coulomb's law28
- Conductors and dielectrics16
- Electric dipole16
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10 Electrostatics questions to practise.
Our own questions, written in the JEE Main pattern and checked, each with an explanation. Pick an option to see the answer.
Q1 · Physics · Electrostatics
A dipole of moment p is placed in a uniform electric field E. Taking the potential energy to be zero when p is perpendicular to E, what is the potential energy when p is parallel to E?
Answer: (A)
The potential energy of a dipole in a uniform field is U = −p·E = −pE cos θ, with the reference U = 0 at θ = 90°. Parallel alignment gives cos θ = 1 and U = −pE, the lowest energy state, which is stable equilibrium.
Q2 · Physics · Electrostatics
An uncharged solid metal sphere is placed in a uniform external electric field E0 directed to the right, and electrostatic equilibrium is reached. What is the electric field at the centre of the sphere produced by the induced surface charges alone?
Answer: (A)
In equilibrium the net field inside a conductor is zero. The net field is the external field E0 plus the field of the induced charges, so E_induced + E0 = 0. Hence E_induced = -E0, which has magnitude E0 and points to the left, opposite to the applied field.
Q3 · Physics · Electrostatics
A solid conducting sphere of radius 2 cm carries a charge of +2 nC. It is surrounded concentrically by a thick, initially uncharged conducting spherical shell of inner radius 5 cm and outer radius 8 cm. The outer surface of the shell is then connected to the earth by a thin wire. Taking the potential at infinity as zero and k = 9 × 10⁹ N m² C⁻², what is the potential of the inner sphere?
Answer: (A)
The inner sphere's +2 nC induces −2 nC on the shell's inner surface (radius 5 cm) and +2 nC on its outer surface. Earthing the shell drives its potential to zero and leaves no charge on the outer surface. The field is nonzero only for 2 cm < r < 5 cm, where E = kQ/r². The shell material is at 0 V, so the sphere's potential equals the potential difference across that gap: V = kQ(1/0.02 − 1/0.05) = 18 × (50 − 20) = 540 V.
Q4 · Physics · Electrostatics
A conductor is in electrostatic equilibrium. The electric field just outside its surface is 3.0 × 10^5 N C^-1 and points normally outward. Take ε0 = 8.85 × 10^-12 C^2 N^-1 m^-2. What is the surface charge density on the conductor at that point?
Answer: (A)
Principle: just outside a charged conductor in electrostatic equilibrium, the field is perpendicular to the surface and has magnitude E = σ/ε0, where σ is the local surface charge density. Rearranging gives σ = ε0E. Substituting E = 3.0 × 10^5 N C^-1 and ε0 = 8.85 × 10^-12 gives σ = 2.66 × 10^-6 C m^-2. Remember that the factor 1/2 applies to the field of a single sheet on one side only, not to a conductor's surface field, and that the field inside the conductor is zero.
Q5 · Physics · Electrostatics
A parallel-plate air capacitor remains connected to a battery while a slab of dielectric constant K is slid in to fill the space between its plates completely. As a result:
Answer: (A)
The battery keeps V fixed, and the capacitance rises from C to KC, so the charge Q = CV becomes K times as large; the battery supplies the extra charge. The field between the plates is E = V/d, and since V and d are both unchanged, so is the field.
Q6 · Physics · Electrostatics
An infinite ladder of identical capacitors, each of capacitance C, is built as follows. Input terminal A is joined through a capacitor C to a node P on the upper wire. Between P and the lower wire (terminal B) there is a capacitor C, and in parallel with it the next identical unit, starting with another series capacitor C on the upper wire followed by a shunt capacitor C, and so on without end. What is the equivalent capacitance between A and B?
Answer: (A)
Adding one more unit to an infinite ladder leaves the capacitance unchanged. Let it be X. The section to the right of node P is the shunt C in parallel with X, giving C + X. This is in series with the input capacitor C, so X = C(C + X)/(2C + X). Cross-multiplying gives X(2C + X) = C² + CX, so X² + CX − C² = 0. The positive root is X = C(√5 − 1)/2 ≈ 0.618C.
Q7 · Physics · Electrostatics
What is the SI unit of dielectric strength, the maximum electric field an insulating material can withstand before it breaks down and begins to conduct?
Answer: (A)
Principle: dielectric strength is the largest electric field a dielectric can sustain without breakdown. Since E = V/d, its unit is V m⁻¹. Identify the quantity as a field, then pick the unit that matches a field rather than a permittivity, a dimensionless ratio, or a surface charge density.
Q8 · Physics · Electrostatics
Four small charges are placed at the corners of a square of side a. Three of the corners carry an identical charge +q. What is the magnitude of the net electrostatic force on the +q charge at the fourth corner, in terms of k = 1/4πε₀?
Answer: (B)
Each of the two adjacent charges is at distance a and exerts a repulsion kq²/a². These two forces are at right angles, so their resultant is √2 kq²/a². It points along the diagonal, away from the opposite corner. The diagonally opposite charge is at distance √2 a and exerts kq²/(2a²) along the same line and in the same direction. The total is (√2 + 1/2) kq²/a².
Q9 · Physics · Electrostatics
Four point charges are fixed at the corners of a square of side a, taken in order around the square: +q, +q, −q, −q. Let k = 1/(4πε₀) and take the potential at infinity as zero. Which option correctly gives the electric potential V and the magnitude of the electric field E at the centre of the square?
Answer: (A)
Each corner is at distance r = a/√2 from the centre, so each charge contributes a field of magnitude kq/r² = 2kq/a². Potential is a scalar: 2(kq/r) − 2(kq/r) = 0. For the field, place +q at (a/2, a/2) and (−a/2, a/2), and −q at (−a/2, −a/2) and (a/2, −a/2). Each +q pushes the field away from itself, and each −q pulls it toward itself. The x-components cancel in pairs, and every charge contributes a component in the −y direction equal to 2kq/a² × cos45°. The total is 4 × (2kq/a²)/√2 = 4√2 kq/a². So V = 0 but E = 4√2 kq/a².
Q10 · Physics · Electrostatics
Two large parallel metal plates 5 mm apart are kept at a potential difference of 200 V. What is the magnitude of the electric field between them?
Answer: (C)
Between large parallel plates the field is uniform and equal to the fall of potential per unit distance: E = V/d = 200 / (5 × 10⁻³) = 4 × 10⁴ V m⁻¹. It points from the plate at higher potential to the plate at lower potential.
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All 237 real JEE Main questions from Electrostatics.
The questions from the actual papers, with the official answer and an explanation for each — chapter by chapter, or as full timed papers.
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About Electrostatics in JEE Main.
How many questions come from Electrostatics in JEE Main?
Electrostatics (Physics, Class 12) has been asked 237 times in the 111 JEE (Main) shift papers from 2020–2025: about 2.1 questions a paper, 8% of all Physics questions. It is the most-asked of 20 Physics chapters. The 2025 shifts had 35 from it in all.
Which topics of Electrostatics are asked most in JEE Main?
Capacitance (81), Electric field and potential (57), Gauss's law (39), Coulomb's law (28), counted over the papers from 2020–2025.
Is Electrostatics important for JEE Main 2027?
It is in the syllabus in force, so it can be asked. By past papers it ranks 1 of 20 in Physics; use that to decide how much time it gets, not whether to study it.
Where can I solve Electrostatics JEE Main previous year questions?
On Nikaalle, free: sign up and practise every past JEE Main question from Electrostatics with an explanation for each, or sit the full papers timed. The ten questions on this page are our own, written in the same pattern.
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