Question

Suppose a wavefront originates from a point source as shown in the figure. Which of the following arrows correctly indicates the direction of propagation of light at point A?

• A. $\downarrow$
• B. $\uparrow$
• C. $\to$
• D. $\leftarrow$

Answer 1

The correct option is C $\to$

The direction of propagation of a wave at a point is perpendicular to the wavefront at that point. If we draw perpendicular (i.e. normal) to the wavefront, at point A, it will point towards the right.

Hence, $\left(C\right)$ is the correct answer.