2016 Electromagnetic WavesSources of electromagnetic waves Easy Question 29 of 49 in Electromagnetic Waves

Out of the following options which one can be used to produce a propagating electromagnetic wave?

A A stationary charge.
B A chargeless particle.
C An accelerating charge.
D A charge moving at constant velocity.

The answer is C.

Solution

Only accelerated charges radiate EM waves.

A stationary charge produces only an electric field, not a magnetic field.
A chargeless particle produces neither an electric nor a magnetic field.
An accelerating charge produces both an electric field and a time-varying magnetic field, which varies with space, leading to generation of an EM wave.
A charge moving at constant velocity produces only constant electric and magnetic fields, so it cannot produce an electromagnetic wave.

Concept accelerating-charge-em-wave

Electromagnetic Waves in past papers

49 questions from this chapter have appeared across 24 exam years.