Speed of EM Waves — MCQ Practice

An electromagnetic wave travels in a medium with relative permittivity $epsilon_r = 9$ and relative permeability $mu_r = 1$. If the speed of light in vacuum is $c = 3 \times 10^8 \,\text{m/s}$, what is the speed of the electromagnetic wave in this medium?

Which of the following statements about the speed of electromagnetic waves is INCORRECT?

If the refractive index of a transparent material is 1.6, what is the speed of light in this material? (Given $c = 3 \times 10^8 \,\text{m/s}$)

An electromagnetic wave has an electric field amplitude $E_0 = 120 \,\text{V/m}$ in vacuum. What is the amplitude of the magnetic field ($B_0$) of this wave?

The frequency of an electromagnetic wave is $6 \times 10^{14} \,\text{Hz}$. If it passes from vacuum into a medium with refractive index 1.5, what will be its wavelength in the medium? (Given $c = 3 \times 10^8 \,\text{m/s}$)

The speed of an electromagnetic wave in a certain non-magnetic dielectric medium is $2.5 \times 10^8 \,\text{m/s}$. What is the relative permittivity ($epsilon_r$) of this medium? (Given $c = 3 \times 10^8 \,\text{m/s}$)