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JEE PHYSICS MCQ: ELECTRIC FIELDS AND CHARGES

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Application +4 | -1

A solid sphere of radius

R

has a charge

Q

distributed in its volume with a charge density

\rho = k\;{r^a}

, where

k

and

a

are constants and

r

is the distance from its centre. If the electric field at

r = \frac{R}{2}

is

\frac{1}{8}

times that at

r = R,

find the value of

a

View answer and explanation

Correct option: C

2

Option C (2) is correct because by applying Gauss's law and comparing the electric fields at r = R/2 and r = R, we can solve for the value of a.

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