EM Wave Propagation — Practice Quiz

Question 1

An EM wave in vacuum has E₀ = 60 V/m. The amplitude of B₀ is:

Accepted Answer

2 × 10⁻⁷ T

Answer

1 × 10⁻⁷ T

Answer

2 × 10⁻⁵ T

Answer

5 × 10⁻⁶ T

Question 2

In an EM wave, the relationship between E, B, and the propagation direction k̂ is:

Accepted Answer

E ⊥ B, both ⊥ k̂, and E × B along k̂

Answer

All three parallel

Answer

E parallel to B, both ⊥ k̂

Answer

E and B both along k̂

Question 3

Light enters glass of index 1.5 from air. Which quantity is UNCHANGED?

Accepted Answer

Frequency

Answer

Speed

Answer

Wavelength

Answer

Wave-number k

Question 4

If the permittivity of a medium is 4ε₀ and permeability is μ₀, the speed of light in the medium is:

Accepted Answer

c/2

Answer

c

Answer

c/4

Answer

2c

Question 5

Which of the following is NOT a property of EM waves in vacuum?

Accepted Answer

Need a medium to propagate

Answer

Transverse

Answer

Speed = c regardless of wavelength

Answer

Carry momentum

Question 6

Hertz's 1887 experiment confirmed:

Accepted Answer

Existence of EM waves outside the visible band

Answer

Polarisation of light

Answer

Photoelectric effect

Answer

Quantum nature of light