Question

1. Electromagnetic waves can be produced by

Select one:

a. None of the previous answers is correct.

b. electric charges in accelerated motion.

c. electric charges moving with constant velocity.

d. All of the previous answers are correct.

e. electric charges at rest.

2.

In an electromagnetic wave the E and B fields are oriented such that

Select one:

a. they are parallel to one another and perpendicular to the direction of wave propagation.

b. they are perpendicular to one another and parallel to the direction of wave propagation.

c. they are perpendicular to one another and perpendicular to the direction of wave propagation.

d. None of the above answers is correct.

e. they are parallel to one another and parallel to the direction of wave propagation.

3.

Which of the following expressions is the correct representation for the speed of light?

Select one:

a. 3/sqrt(e0 u0)

b. sqrt(e0/u0)

c. sqrt(e0 u0)

d. sqrt(u0 e0)

e. 1/sqrt(e0 u0)

Answer 1

1) A charge in accelerated motion produces EM waves.

Charge at rest produces only electric field and constant moving charge does produce both electric field and magnetic field but it does not radiate energy ( EM wave) . (ANSWER : B)

2) In an EM wave, E and B oscillate perpendicular to each other and also to the direction of the wave propagation. ( ANSWER : C)

3) speed of light ,