JEE Main 2025 · PhysicsMultiple choiceSingle correctEasyApplication

JEE Main 8 April 2025, Shift 2, Physics Q38

Question 38 of 75 in this shift, Physics question 13 of 25, Section A.

Two metal spheres of radius R and 3R have same surface charge density

\sigma

. If they are brought in contact and then separated, the surface charge density on smaller and bigger sphere becomes

\sigma_1

and

\sigma_2

, respectively . The ratio

\frac{\sigma_1}{\sigma_2}

(1)9
(2) $\frac{1}{3}$
(3)3Official answer
(4) $\frac{1}{9}$

Official answer

Option 3

NTA final key.

Chapter: Electric Charges and Fields
Topic: Conductors in Fields
Idea tested: Surface Charge Density Ratio of Connected Spheres

Same topic in other shifts

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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. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.