Question

If charge is distributed uniformly in xy plane with charge density to in first quardrant and $-\sigma$ in remaining three quadrants, then work done by electric field in moving a point charge q from $(0,0,d)$ to $(0,0,2d)$ is:

• A. $\frac{-\sigma q}{4{\epsilon }_0}d$
• B. $\frac{\sigma q}{4{\epsilon }_0}d$
• C. $\frac{-\sigma q}{2{\epsilon }_0}d$
• D. $\frac{\sigma q}{{\epsilon }_0}d$

Answer 1

Answer: (A)

As due to $2$ part of plane
$E=\frac{-\sigma }{4{\epsilon }_0}$
$\Rightarrow W=qEd$
$W=\frac{-\sigma qd}{4{\epsilon }_0}$