Question

Two infinite sheets of uniform charge density $+\sigma$ and $-\sigma$ are parallel to each other as shown in the
figure. Electric field at the

• A. points to the left or to the right of the sheets is zero.
• B. midpoint between the sheets is zero
• C. midpoint of the sheets is $\sigma /{\epsilon }_0$ and is directed towards right.
• D. midpoint of the sheet is $2\sigma /{\epsilon }_0$ and is directed towards right.

Answer 1

Answer: (A), (C)

The correct options are
A points to the left or to the right of the sheets is zero.
C midpoint of the sheets is $\sigma /{\epsilon }_0$ and is directed towards right.

Electric felid to the point to the left or to the right of the sheet = 0

Electric feild in the muddle of sheets =$\frac{\sigma }{2{\epsilon }_0}\hat{i}+\frac{\sigma }{2{\epsilon }_0}\hat{i}=\frac{\sigma }{{\epsilon }_0}\hat{i}$

left of positive sheet

$E=\frac{\sigma }{2{\epsilon }_0}(-\hat{i})$ due to +ve sheet $+\frac{\sigma }{2{\epsilon }_0}\left(\hat{i}\right)$ due to the -ve sheet

Right of negative sheet = o

$E=\frac{\sigma }{2{\epsilon }_0}\hat{i}-\frac{\sigma }{2{\epsilon }_0}\hat{i}E=0$