JEE Main 2020 · PhysicsMultiple choiceDiagram basedHardMulti-step

JEE Main 8 January 2020, Shift 2, Physics Q11

Question 11 of 75 in this shift, Physics question 11 of 25, Section A.

A capacitor is made of two square plates each of side 'a' making a very small angle

\alpha

between them, as shown in figure. The capacitance will be close to :

The figure, in words

Two plates drawn edge-on: a lower horizontal line and an upper line slightly inclined upward to the right, with the angle between them marked alpha at the right; upper line labelled V1 at its right end, lower line labelled V2 at its right end. A dash-dot horizontal reference line at the height of the left end of the upper plate, a vertical dashed line at the right, an arrow labelled 'd' at the left between the plates, and a horizontal arrow labelled 'a' along the lower plate.

(1) $\frac{\epsilon_0 a^2}{d}\left(1-\frac{3\alpha a}{2d}\right)$
(2) $\frac{\epsilon_0 a^2}{d}\left(1-\frac{\alpha a}{2d}\right)$ Official answer
(3) $\frac{\epsilon_0 a^2}{d}\left(1+\frac{\alpha a}{d}\right)$
(4) $\frac{\epsilon_0 a^2}{d}\left(1-\frac{\alpha a}{4d}\right)$

Official answer

Option 2

NTA final key (Jan 2020).

Chapter: Electrostatic Potential and Capacitance
Topic: Parallel Plate Capacitors
Idea tested: Capacitance with a Small Tilt Angle

Same topic in other shifts

All Parallel Plate Capacitors questions

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.