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

• A

  0 volt/metre
• B

  $\sigma / 2 \varepsilon_0$ volt $/$ metre
• Correct answer
  C

  $\sigma / \varepsilon_0$ volt $/$ metre
• D

  $2 \sigma / \varepsilon_0$ volt/metre.

Solution

Electric field between the plates is $$ \begin{aligned} & =\frac{\sigma}{2 \varepsilon_0}-\frac{(-\sigma)}{2 \varepsilon_0} \\ & =\frac{\sigma}{\varepsilon_0} \text { volt } / \text { meter } \end{aligned} $$

Hence, the correct answer is option: 'C'.