Question

A sphere of uniform density has a spherical cavity inside it, then

• A. field inside cavity will be constant.
• B. region of cavity may be equipotential.
• C. region of cavity may not be equipotential.
• D. field inside cavity may be zero.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A field inside cavity will be constant.
B region of cavity may be equipotential.
C region of cavity may not be equipotential.
D field inside cavity may be zero.




Field at P = Field due to $S_1$ - Field due to $S_2$
Field inside a sphere is proportional to distance from the radius.
$\therefore$ Field at $P=k{\overrightarrow{r}}_1-k{\overrightarrow{r}}_2$
$=k({\overrightarrow{r}}_1-{\overrightarrow{r}}_2)=k\overrightarrow{O_1{O}_2}$
Which is a constant.