JEE PYQ: Electrostatics Question 47
Question 47 - 2019 (12 Apr Shift 1)
Shown in the figure is a shell made of a conductor. It has inner radius $a$ and outer radius $b$, and carries charge $Q$. At its centre is a dipole $\vec{P}$ as shown. In this case:
(1) surface charge density on the inner surface is uniform and equal to $\frac{Q/2}{4\pi a^2}$
(2) electric field outside the shell is the same as that of a point charge at the centre of the shell
(3) surface charge density on the outer surface depends on $|\vec{P}|$
(4) surface charge density on the inner surface of the shell is zero everywhere
Show Answer
Answer: (2)
Solution
The dipole induces charges on the inner surface of the conductor, but the net induced charge on the inner surface is zero. The outer surface has charge $Q$ uniformly distributed (since the conductor shields the dipole field). Outside, the field is that of a point charge $Q$ at the centre.
BETA
