Question

In a plane eelctro magnetic wave,the amplitude of the magnetic field is 5x10^-6 t.Find the amplitude of the electric field and the total averageenergy density of the wave

Answer 1

Answer:

The relation between Eo(electric field amplitude) and Bo(magnetic field amplitude) in EM wave is

Eo = cBo

c = 3 x 10^8 m/s

Bo = 5 x 10^-6 T

Eo = 3 x 10^8 m/s x 5 x 10^-6 T = 1500V/m

(1). Eo = 1500V/m

Energy density of an EM wave

(2). Energy density = (1/2)*ε0*E^2

ε0 = 8.85 x 10^-12

Energy = (1/2)*(8.85 x 10^-12)*(1500^2)

Energy density of EM = 9.96 x 10^-6 J/m^3