question_answer

A parallel plate capacitor has two square plates with equal and opposite charges. The surface charge densities on the plates are \[+\sigma \] and \[-\sigma \] respectively. In the region between the plates the magnitude of the electric field is

A)  \[\frac{\sigma }{2{{\varepsilon }_{0}}}\]

B)  \[\frac{\sigma }{{{\varepsilon }_{0}}}\]

C)  zero            

D)  None of these

Correct Answer: B

Solution :

The magnitude of the electric field \[E=\frac{1}{2{{\varepsilon }_{0}}}[\sigma (-\sigma )]\] \[E=\frac{2\sigma }{2{{\varepsilon }_{0}}}\] \[E=\frac{\sigma }{{{\varepsilon }_{0}}}\]