Target Exam

CUET

Subject

Physics

Chapter

Electromagnetic Waves

Question:

Electromagnetic wave travels with speed of 2.0 × 108 m/s in any medium of relative permeability (µr) 1.5. Find the relative permittivity of the medium (∈r)

Options:

1.25

1.50

2.25

2.50

Correct Answer:

1.50

Explanation:

Refractive Index $ n = \frac{c}{v} = 1.5$

$ n^2  = \mu_r \epsilon_r$

$ \epsilon_r = \frac{n^2}{\mu_r} = \frac{1.5^2}{ 1.5} = 1.5$