question_answer

Two infinitely long parallel conducting plates having surface charge densities \[+\sigma \]and\[-\sigma \]respectively, are separated by a small distance. The medium between the plates is vacuum. If \[{{\varepsilon }_{0}}\]is the dielectric permittivity of vacuum, then the electric field in the region between the plates is               [AIIMS 2005]

A)            \[0\,volts/meter\]

B)                                      \[\frac{\sigma }{2{{\varepsilon }_{o}}}volts/meter\]

C)            \[\frac{\sigma }{{{\varepsilon }_{o}}}volts/meter\]

D)                                      \[\frac{2\sigma }{{{\varepsilon }_{o}}}volts/meter\]

Correct Answer: C

Solution :

                     Electric field between the plates is            \[=\frac{\sigma }{2{{\varepsilon }_{0}}}-\frac{(-\sigma )}{2{{\varepsilon }_{0}}}\]                    \[=\frac{\sigma }{{{\varepsilon }_{0}}}volt/meter\]