The electric field of a plane electromagnetic wave varies with time of amplitude `2Vm^-1` propagating along z-axis. The average energy density of the magentic field is (in `Jm^-3`)

Options

A. `13.29 xx 10^(-12)`
B. `8.86 xx 10^(-12)`
C. `17.72 xx 10^(-12)`
D. `4.43 xx 10^(-12)`

Answer

C

Explanation

Average energy density = `(1)/(2)(B^(2))/(mu_(0))= (1)/(2)(E_(0)^(2))/(mu_(0)c^(2))= (1)/(2) xx 8.85 xx 10^(-12) xx (2)^(2) = 17.72 xx 10^(-12)`