Chapter 26, Problem 44A

To determine

To explain: An oscillator is used to produce electromagnetic waves.

Whether electromagnetic waves will be created if a battery or a DC generator were used.

Explanation of Solution

Introduction:

The electromagnetic wave is also known as the EM wave. Electromagnetic waves may also be said to be the composition of oscillating electrical and magnetic fields. It consists of both electric and magnetic fields. There is a sinusoidal graph displaying the electromagnetic waves. It consists of time-varying electrical and magnetic fields perpendicular to each other, and also perpendicular to wave propagation direction.An oscillator is a circuit that generates a waveform that alternates constantly, repeatedly without any input.

The propagation of electromagnetic waves in space is the propagation of an alternate regeneration of time-varying electric and magnetic fields in space or medium. Since AC voltage varies with time, so it can able to generate an electric and magnetic field which varies with time.

On the other hand, DC voltage doesn’t vary with time, so it is not able to generate a time-varying electric field; hence it can’t generate a time-varying magnetic and electric field. But in case, when DC generator is just turned on or just turned off, then DC voltage varies with time, therefore it can generate a time-varying electric and magnetic field. Thus it can produce an electromagnetic wave in this case only.

Conclusion:

Hence, AC voltage varies with time, so it can able to generate an electric and magnetic field which varies with time and thus can generate electromagnetic waves. If only DC generator is just only turn off/on, then electromagnetic waves are produced.