Question

The voltage can be increased, but electric breakdown will occur if the electric field inside the capacitor becomes too large. The capacity can be increased by

• A. expanding the electrode areas
• B. reducing the gap between the electrodes
• C. expanding the gap between the electrodes
• D. Both A and B

Answer 1

Answer: (D)

The capacitance of an air filled parallel plate capacitor is given by:

$C=\frac{{\epsilon }_{0}A}{d}$ ..........................eq1

where $A=$ area of each plate (electrode),

$d=$ distance between plates (electrodes)

from eq1 ,

$C\propto A$

It is clear that capacity C can be increased by expanding the electrodes area,

and $C\propto 1/d$ ,

hence, capacity C can be increased by reducing the gap between the electrodes.