Question

The surface density on a copper sphere is $\sigma$. The electric field strength on the surface of the sphere is:

• A. $\sigma$
• B. $\sigma /2$
• C. $\sigma /2{\epsilon }_0$
• D. $\sigma /{\epsilon }_0$

Answer 1

The correct option is D $\sigma /{\epsilon }_0$

From Gauss Law, $\int EdA=\frac{Q_{enc}}{{\epsilon }_0}$

$E\times A=\frac{\sigma A}{{\epsilon }_0}$

therefore we get,

$E=\frac{\sigma }{{\epsilon }_0}N/C$.