Q.
Three large parallel plates have uniform surface change densities as shown in the figure. Find the electric field at point $P.$
A) $\frac{- 4\sigma}{{\ \ \ \varepsilon}_{0}}\widehat{k}$
B) $\frac{4\sigma}{{\ \ \varepsilon}_{0}}\widehat{k}$
C) $\frac{- 2\sigma}{{\ \ \ \varepsilon}_{0}}\widehat{k}$
D) $\frac{2\sigma}{{\ \ \ \varepsilon}_{0}}\widehat{k}$
Explanation
(c) Here,
$\overrightarrow{E} = {\overrightarrow{E}}_{1} + {\overrightarrow{E}}_{2} + {\overrightarrow{E}}_{3} = \left( + \frac{\sigma}{2\varepsilon_{0}} \right)\left( - \widehat{k} \right)$+$\ \left( \frac{2\sigma}{2\varepsilon_{0}} \right)\left( - \widehat{k} \right)$+$\ \left( \frac{\sigma}{2\varepsilon_{0}} \right)\left( - \widehat{k} \right)$
$= \ - \left( \frac{2\sigma}{\varepsilon_{0}} \right).\widehat{k}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.