Question

Which of the following statements is NOT true about electromagnetic waves?

Select the correct answer
a. Choose this answer if all of the statements are true
b. The magnetic field always points in a direction perpendicular to the electric field
c. Light can be considered to be an electromagnetic wave
d. The velocity they travel depends on the magnitudes of the electric and magnetic fields
e. Radio waves can be considered to be electromagnetic waves

Answer 1

The incorrect statement about electromagnetic waves is that their velocity depends on the magnitudes of the electric and magnetic fields; the velocity is actually constant and equals the speed of light, c.

Step-by-step explanation:

The statement 'The velocity they travel depends on the magnitudes of the electric and magnetic fields' is NOT true about electromagnetic waves. Electromagnetic waves, such as light and radio waves, are transverse waves made up of perpendicular electric (E) and magnetic (B) fields to each other and to the direction of wave propagation. The speed of an electromagnetic wave is the speed of light, c, which is determined by the electric constant (ε) and the magnetic constant (μ) as c = 1/√(εμ), and is independent of the magnitudes of the electric and magnetic fields. Therefore, statement d is incorrect while statements b, c, and e are all true.