Question

Positive charge q is given to each plate of a parallel plate air capacitor having area of each plate A and separation between them, d. Then find Energy stored between the plates:

• A. $\frac{1}{2}.\frac{q^2}{C}$
• B. $\frac{1}{3}.\frac{q^2}{C}$
• C. $\frac{1}{2}.\frac{q}{C}$
• D. $\frac{1}{2}.\frac{q^3}{C}$
• E. $\frac{1}{2}.\frac{q^4}{C}$

Answer 1

The correct option is A $\frac{1}{2}.\frac{q^2}{C}$

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

$q$; each plate charge

$q=CV$

$E\frac{V}{d}=\frac{q}{Cd}$

$V=\frac{q}{C}$

$E=\frac{1}{2}C{V}^2=\frac{1}{2}.\frac{q^2}{C}$