This chapter has 24 PYQs from 2018–2024, split across five subtopic pages below. Each page gives you the minimum theory, then a step-by-step solution to every question.
Subtopic pages
- Gauss law — flux, Gauss theorem (×4), differential form, dipole flux
- Fields by Gauss — solid sphere, U-nucleus surface field, cylinder, zero-E point
- Potential & dipole — dipole + moment, V(r,θ), conservative field
- Capacitors — ½CV², K-slab, spherical, cylindrical, energy loss
- Dielectrics — D = ε₀E + P, polarization, polar vs non-polar
How every PYQ reads on this site
Q1 201820192023×3 Write down the relation between D, P and E in a dielectric medium, and show that D = ε₀E + P.
Recall. Polarisation P is dipole moment per unit volume. Displacement D is the free-charge field. …
Step 1. Take a dielectric slab of area A, thickness d between parallel plates with free charge +Q. … Step 2. Bound charges ±σ_p appear on the faces, where σ_p = P. … Step 3. The net field inside is E = (σ_free − σ_p)/ε₀ = (D − P)/ε₀. …
Answer. $\boxed{\vec{D} = \varepsilon_0\vec{E} + \vec{P}}$.
Exam tip: write “free charge vs bound charge” line first — that is where 2 of the 5 marks sit.
Each page follows that pattern. Read theory → skim an example → re-read the steps in your own words → redo without looking.
Most repeated
- Gauss theorem + differential form — ×4 (2018, 2019, 2022, 2023)
- D = ε₀E + P — ×3
- Solid sphere by Gauss — ×2
Reference
Brij Lal & N. Subrahmanyam — Electricity & Magnetism Ch-1–4. S.L. Arora Vol-1 Ch-1, 2. Fallback: D.J. Griffiths Ch-2 (only for ∇ forms).