The rms value of the electric field of the light from the sun is `720 N//C` The total energy density of the electromagnetic wave is

Options

A. `3.3 xx 10^(-3)` J/`m^(3)`
B. `4.58 xx 10^(-6)` J/`m^(3)`
C. `6.37 xx 10^(-9)` J/`m^(3)`
D. `81.35 xx 10^(-12)` J/`m^(3)`

Answer

B

Explanation

`U_(av) = (1)/(2) epsilon_(0) E_("max")^(2)`