Which of the following has zero average value in a plane electromagnetic wave?

(A) Electric field
(B) Magnetic field
(C) Electric energy
(D) Magnetic energy

Choose the correct answer from the options given below.

(A) and (B) only

The correct answer is Option (4) → (A) and (B) only

In a plane electromagnetic wave:

→ The electric field (E) and magnetic field (B) are sinusoidal functions of time.

→ Their instantaneous values vary periodically and average to zero over a complete cycle.

→ The electric energy and magnetic energy are proportional to $E^2$ and $B^2$, respectively, so they are always positive and have nonzero average values.

∴ Correct options:(A) Electric field and (B) Magnetic field