A plane electromagnetic wave traveling in the positive direc

A plane electromagnetic wave traveling in the positive direction of an x axis in vacuum has components E_x = E_y = 0 and E_z = (4.2 V/m) cos[(pi times 10^15 s^-1)(t - x/c)]. What is the amplitude of the magnetic field component? Your answer cannot be understood or graded. More Information T

Solution

B = E/c

=> Bx = By = 0 ( as Ex, Ey = 0 )

=> Bz = 4.2/(3*10^8) = 1.4*10^-8 T