First slide

Nature of electromagnetic wave

Question

A plane electromagnetic wave
$E_{z} = 100 \cos (6 \times 10^{8} t + 4 x) V / m$
propagates in a medium of dielectric constant. The refractive index of the medium is

Easy

A

1.5
B

2.0
C

2.4
D

4.0

Solution

Comparing the given equation with equation of plane electromagnetic wave, $E_{z} = E_{0} \cos (ωt + kx)$ we have $ω = 6 \times 10^{- 8} and k = 4$
Velocity of light in medium
$v = \frac{ω}{k} = \frac{6 \times 10^{8}}{4} = \frac{3}{2} \times 10^{8} m / s$
Refractive index, $μ = \frac{c}{v} = \frac{3 \times 10^{8}}{(3 / 2) \times 10^{8}} = 2$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App