JEE · NEET Previous Year Question

Let there be a spherically symmetric charge distribution with charge density varying as upto r = R, and ρ(r) = 0 for r > R, where r is the distance from the origin. The electric field at a distance r (r < R) from the origin is given by

Topic: JEE PYQ

Answer: B. Full step-by-step solution below.

  1. A
  2. B
  3. C
  4. D

Correct answer: B

Solution

(b) Consider a spherical shell of radius x and thickness dx.
Charge on it dq
dq = ρ × 4πx2. dx
dq = ρ0 x 4πx2 dx
q = 4πρ0
q = 4 ρ0
E = = × 4πρ0
E =

More Capacitance PYQs