Q.

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of 2.0×1010 Hz and amplitude 48 Vm-1. Then the amplitude of oscillating magnetic field is
(Speed of light in free space = 3×108 ms-1)                    [2023]

1 1.6×10-7T  
2 1.6×10-6T  
3 1.6×10-9T  
4 1.6×10-8T  

Ans.

(1)

Frequency of E.M. wave, υ=2.0×1010Hz

Electric field amplitude, E0=48Vm-1

Speed of light, c=3×108m/s

Magnetic field strength is given as:

B0=E0c=483×108=1.6×10-7T