Question

The electric field of an electromagnetic wave in free space is given by vector E = 10 cos(10^7 t + kx)j V/m,

Answer 1

EM waves are transverse waves.  The transverse waves are those in which direction of disturbance or displacement in the medium is perpendicular to that of the propagation of wave.   The particles of the medium are moving in a direction perpendicular to the direction of propagation of wave.