AP EAMCET201921 Apr 2019Evening ShiftPhysicsElectromagnetic WavesActual
The amplitude of the electric field in a parallel beam of plane electromagnetic waves of intensity 53 . 1 Wm - 2 is (Permittivity of free space = 8 . 85 × 10 - 12 C 2 N - 1 m - 2 )
Options
- A400 NC - 1
- B50 NC - 1
- C100 NC - 1
- D200 NC - 1
Correct answer
D. 200 NC - 1
Step-by-step solution
The expression for the electromagnetic wave is, I = 1 2 ε 0 E 0 2 c Rewrite the above equation. E 0 = 2 I ε 0 c Substitute the values in the above equation. E 0 = 2 × 53 . 1 8 . 85 × 10 - 12 × 3 × 10 8 = 200   N   C - 1