Question

A circular metal plate has radius $2.0m$ and negligible thickness. It is given a charge $40mC$. electric field at a point close to the plate and near its centre is nearest to

• A. $0.9\times 10^{8}V/m$
• B. $1.8\times 10^{8}V/m$
• C. $3.6\times 10^{8}V/m$
• D. $7.2\times 10^{8}V/m$

Answer 1

Answer: (C)

$E=\sigma /{\epsilon }_0$ and $\sigma =q/\pi r^2$ . Hence $E=q/\pi {\epsilon }_0{r}^2$