Discussion Forum



1)

 A hollow insulated conduction sphere is given a positive charge of 10 μC. What will be the electric field at the centre of the sphere if its radius is 2 metres?


A) Zero

B) $5\mu Cm^{-2}$

C) $20\mu Cm^{-2}$

D) $8\mu Cm^{-2}$

Answer:

Option A

Explanation:

Charge resides on the outer surface of a conducting hollow sphere of radius R. We consider a spherical surface of radius r < R. By Gauss theorem

2152021866_201441_195748_ans_0af39cd3dda240a1b6fa1510490dd721.png

$\int_{s}^{} \vec{E}.\vec{d}s = \frac{1}{\epsilon_{0}}$× Charge enclosed or

$E\times4\pi r^{2} =\frac{1}{\epsilon_{0}}\times0$

i.e electric field inside a hollow sphere is zero.