question_answer

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 [AIPMT (M) 2010]

A) become zero

B) increase

C) decrease

D) remain same

Correct Answer: C

Solution :

[c]

The electric field in vacuum

\[{{E}_{0}}=\frac{\sigma }{2{{\varepsilon }_{0}}}\]

When the plates are dipped in kerosene oil tank, then the electric field between the plate will be

\[E=\frac{\sigma }{2{{\varepsilon }_{0}}k}\]

\[\because \]       \[k>1\]

\[\therefore \]      \[E<{{E}_{0}}\]

So, the electric field between the plates will decrease.