Answer
(a) x direction
(b) z direction
(c) positive y direction
Work Step by Step
(a) We know the electric field propagates parallel to the oscillations. In this case, the electric charge on the x-axis oscillates at the same time about the origin. Thus, the electric field oscillates in the x-direction.
(b) We know that the electric field direction is x and the direction of propagation is +y. Thus, the only direction perpendicular to x and y directions is the z direction and hence the magnetic field oscillates in the z direction.
(c) The observer is located at a point on the +y axis and the light travels in straight line. Hence, the electromagnetic waves should travel in the +y direction.
