Question

Three large parallel plates have uniform surface charge densities as shown in the figure. The electric field intensity at point P is :

• A. $-\frac{4\sigma }{{ϵ}_0}\hat{k}$
• B. $\frac{-3\sigma }{2{\epsilon }_0}\hat{k}$
• C. $\frac{5\sigma }{2{\epsilon }_0}\hat{k}$
• D. $-\frac{5\sigma }{2{\epsilon }_0}\hat{k}$

Answer 1

The correct option is D $-\frac{5\sigma }{2{\epsilon }_0}\hat{k}$

Resultant electric field at point P
$==(\frac{\sigma }{2{ϵ}_0}+\frac{\sigma }{2{ϵ}_0}+\frac{3\sigma }{2{ϵ}_0})(-\hat{k})$
$=-\frac{5\sigma }{2ϵ}\hat{k}$
Ans:(D)