Question

A conductor with a cavity is charged positively and its surface charge density is $\sigma $ . If $E$ and $V$ represent the electric field and potential, then inside the cavity

• A. $E=0$ and $V=0$
• B. $E=0$ and $\sigma =$ constant
• C. $V=0$ and $\sigma =$ constant
• D. $E=0$ and $V=\text{constant}$

Answer 1

Answer: (D)

Surface charge density $=\sigma $
Inside the surface of the conductor, the electric field is zero.
$\Rightarrow \, E_{i n s i d e}=0$
Therefore, $V_{i n s i d e}=V_{s u r f a c e}$
The potential inside the surface of charged sphere is constant
$\text{Hence,}E=0, \, V=$ constant.