The amplitude of the electric field in a parallel beam of plane electromagnetic waves of intensity 53.1 W `m^(-1)` is
(Permittivity of free space `= 8 . 85 xx 10 ^(-12) C^(2) N^(-1) M^(-2)` )

Options

A. `400 NC^(-1)`
B. `50 NC^(-1)`
C. `100 NC^(-1)`
D. `200 NC^(-1)`

Answer

D

Explanation

Given ,
intensity of electromagneitc wave , I = 531 W`m^(-2)`
Premittivity of free space,
`epsilon_(0) = 8 . 85 xx 10 ^(-12) C^(2) N^(-1) M^(-2)`
Intensity of electromagnetic wave, `I = (1)/(2)epsilon_(0) E _(0) ^(2) c`
where , `E_(0)` = amplitude of the electric field. `E(0) = sqrt((2I)/(in_(0) c)) = sqrt((2 xx 53.1)/(8.85 xx 10^(-12) xx 3 xx 10 ^(8)))`
`E_(0) = 200 NC^(-1)`