Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Electromagnetic Waves

Question:

The dielectric constant of air is 1.006. The speed of Electromagnetic Wave travelling in air is $a × 10^8 ms^{-1}$, where a is about 

Options:

3

3.88

2.5

3.2

Correct Answer:

3

Explanation:

For an Electromagnetic Wave (in vacuum),

$Velocity \, c =\frac{1}{\sqrt{\mu_0ε_0}}= 3 × 10^8 ms^{-1}$

Air acts almost as vacuum, hence

$a = 3(approx)$