Question

What is the charge per unit area in ${\text{C/m}}^2$ of an infinite plane sheet, if the electric field produced by the sheet has magnitude $3\text{N/C}$ ?
(Take ${ϵ}_o=9\times {10}^{-12}{\text{C}}^2/{\text{N-m}}^2$)

• A. $3.4\times {10}^{-11}$
• B. $4.4\times {10}^{-11}$
• C. $5.4\times {10}^{-11}$
• D. $6.4\times {10}^{-11}$

Answer 1

The correct option is C $5.4\times {10}^{-11}$

We know that, electric field near infinite plane sheet of charge is given by

$E=\frac{\sigma }{2{ϵ}_0}$

$\Rightarrow 3=\frac{\sigma }{2\times 9\times {10}^{-12}}$

$\Rightarrow \sigma =5.4\times {10}^{-11}{\text{C/m}}^2$

So, $\left(c\right)$ is correct choice.