Question

Electric field intensity at a point due to an infinite sheet of charge having surface charge density $\sigma$ is $E$. If the sheet were conducting, electric intensity would be

• A. $\frac{E}{2}$
• B. $2E$
• C. $E$
• D. $4E$

Answer 1

Answer: (B)

Normal sheet

Apply gauss theorem

$E\cdot (2\cdot A)=\frac{A\cdot \sigma }{{\epsilon }_0}$

$E=\frac{\sigma }{2{\epsilon }_0}$

Conducting sheet

We know inside a conductor E is zero.

$\therefore E\cdot \left(A\right)=\frac{A\cdot \sigma }{{\epsilon }_0}$

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

$\therefore E_{conducting}=2E_{normalsheet}$