The electric field in a plane electromagnetic wave is given by Ez = 60\cos(5x + 1.5 imes 10^{9}t) V/m. Then the expression for the corresponding magnetic field is (here the subscripts denote the dir

Question

The electric field in a plane electromagnetic wave is given by Ez = 60\cos(5x + 1.5 	imes 10^{9}t) V/m. Then the expression for the corresponding magnetic field is (here the subscripts denote the direction of the field):

Vishal Gupta · Accepted Answer

A. B0 = \frac{E0}{c} = \frac{60}{3	imes10^{8}} = 2	imes10^{-7} T. The wave travels along -x (phase 5x + \omega t); with \vec{E} along z, \vec{E}	imes\vec{B} must point along -x, which requires \vec{B} along +y. So By = 2	imes10^{-7}\cos(5x + 1.5	imes10^{9}t) T.

Electromagnetic Waves

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