The voltage of clouds is ` 4 xx 10 ^( 6 ) ` volt with respect to ground. In a a lightening strike lasting 100 m sec, a charge of 4 coulomb is delivered to the ground. The power of lightening strike is

Options

A. 160 MW
B. 80 MW
C. 20 MW
D. 500 KW

Answer

B

Explanation

Work done `=1/(2) Cv^2 =1/2 xxqV =1/2 xx 4 xx 4 xx10^6`
`= 8 xx10^6 J`
Power `(P) =W/t =(8xx10^6)/(100xx10^(-3))=8xx10^7 `= 80 MW