Question

A solid metal sphere of radius $R$ having charge $q$ is enclosed inside the concentric spherical shell of inner radius a and outer radius $b$ as shown in figure. The approximate variation electric field $\vec{ E }$ as a function of distance $r$ from centre $O$ is given by

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

Considering outer spherical shell is nonconducting
Electric field inside a metal sphere is zero.
$ r < R \Rightarrow E =0 $
$ r > R \Rightarrow E =\frac{ kQ }{ r ^{2}}$

Option (2)
Considering outer spherical shell is conducting

$r < R , E =0$
$R \leq r < a$
$a \leq r < b$
$r \geq b$
$E =\frac{ kQ }{ r ^{2}}$
$E =0$
$E =\frac{ kQ }{ r ^{2}}$

Option (1)