Question

When light propagates in vaccum there is an electric field and a magnetic field. Which of the following is not true about these field?

• A. They are constant in time
• B. They have zero average value
• C. They are perpendicular to the direction of propagation of light
• D. They are mutually perpendicular

Answer 1

The correct option is A They are constant in time

$Answer:-$ A

They vary with time following a wave function (sinuosoidal) and average value of these function is zero and also we can see in figure they are mutually perpendicular and also perpendicular to direction of propagation.