Question

If the distance between the place of a parallel plate capacity $10\mu F$ is doubled, then new capacity will be:

• A. $5\mu F$
• B. $20\mu F$
• C. $10\mu F$
• D. $15\mu F$

Answer 1

The correct option is A $5\mu F$

The capacitance of parallel plate capacitor, $C=\frac{A{ϵ}_o}{d}$

where $d$ is the distance between the plates.

$⟹$ $\frac{C^{\prime }}{C}=\frac{d}{d^{\prime }}$ (for $A=$ constant )

Given : $d^{\prime }=2d$ $C=10\mu F$

$\therefore$ $\frac{C^{\prime }}{10}=\frac{d}{2d}$ $⟹C^{\prime }=5\mu F$