Question

In a plane electromagnetic wave, which of the following quantities given below has/have non zero average value in one complete cycle?
a. Magnetic field
b. Electric field
c. Magnetic energy
d. Electrical energy

Answer 1

In a plane electromagnetic wave, which of the following quantities given below has/have non zero average value in one complete cycle?

a. Magnetic field

b. Electric field

c. Magnetic energy✔️✔

d. Electrical energy✔️✔️

Answer 2

In a plane electromagnetic wave, both Magnetic energy and Electrical energy have non-zero average values in one complete cycle.

• The reason is that both magnetic energy and electrical energy are sinusoidal in nature.
• The average value of sinusoidal wave is zero.
• They both are cyclic because of the sin and cos functions so their average value over the complete cycle is zero.

So, the answer will be both c). and d).