Question

A parallel plate air capacitor is made using two square plates each of side $0.2\text{m}$, spaced $1\text{cm}$ apart. It is connected to a $50\text{V}$ battery. What is the charge on each plate?

• A. $3.54\times {10}^{-3}\text{C}$
• B. $1.77\times {10}^{-3}\mu \text{C}$
• C. $1.77\times {10}^{-3}\text{C}$
• D. $3.54\times {10}^{-3}\mu \text{C}$

Answer 1

The correct option is B $1.77\times {10}^{-3}\mu \text{C}$

Charge on each plate is:

$Q_0=CV$

$\Rightarrow Q_0=\frac{{ϵ}_{0}A}{d}\times V$

$\Rightarrow Q_0=\frac{8.85\times {10}^{-12}\times 0.2\times 0.2}{{10}^{-2}}\times 50$

$Q_0=1.77\times {10}^{-3}\mu C$