Question

The distance between the plates of a parallel
Plate capacitor is 'd . Another thick meta. plate of thickness 1/2 and area same as that of plates is so placed. between the plates, that it does not touch them. The capacity of the resulting capacitor.

• A. remains the same
• B. becomes double
• C. becomes half
• D. becomes one fourth

Answer 1

The correct option is B becomes double

$C=\frac{A{\epsilon }_o}{d}$

In second case

$C^{\prime }=\frac{A{\epsilon }_o}{d(1-\frac{1}{2})}$

$=\frac{2A{\epsilon }_o}{d}=2C$

$C^{\prime }=2C$

Capacity becomes doubles.