Question

In which direction does the wave \[B_y=(2\times10^{-7})\sin(0.5\times10^3x+1.5\times10^{11}t)\] propagate?

Options

• The positive y-direction

• The negative x-direction

• The positive z-direction

• The positive x-direction

Answer 1

A fixed phase requires position to decrease as time increases because the phase contains a positive time term. The wave therefore propagates in the negative x-direction.