Question

Two parallel metal plates having charges +Q and -Q face each other at a certain distance between them. If the plates are now dipped in kerosene oil tank, the electric field between the plates will :

• A. decrease
• B. become zero
• C. increase
• D. remains same

Answer 1

Answer: (A)

Electric field between two parallel plates placed in vacuum is given by
E = $\frac{\sigma }{{\epsilon }_0}$
In a medium of dielectric constant K, E' = $\frac{\sigma }{{\epsilon }_{0}K}$ For kerosene oil K > 1$\Rightarrow$ E' is less than E