Question

when a positive charge inside a metallic shell of thickness t is moved then induced surface charge density

Answer 1

According to the question the charge is placed inside the metallic shell of thickness t

We know,

For a charge kept inside the shell induced charge is given as

${\sigma }_{out}=\frac{q}{4\pi {(a+t)}^2}$

And

${\sigma }_{in}=\frac{q}{4\pi a^2}$