Question

The voltage of clouds is $4\times 10^{6}V$ with respect to ground. In a lightning strike lasting $100ms$, a charge of $4C$ is delivered to the ground. The power of lightning strike is

• A. $160MW$
• B. $80MW$
• C. $20MW$
• D. $500kW$

Answer 1

Answer: (A)

Work done in delivering $q$ coulomb of charge from clouds to ground,
$W=Vq$
$=4\times 10^6\times 4$
$=16\times 10^{6}J$
The power of lightning strike,
$P=\frac{W}{t}=\frac{16\times 10^6}{0.1}=160\times 10^{6}W=160MW$