A dielectric medium has a relative permittivity ϵr = 6, for this the values of Index of Refraction and Phase velocity are given

(A) η = 6

(B) η = 2.45

(C) Phase Velocity = 3 × 108 m/s

(D) Phase Velocity = 1.22 × 108 m/s

Choose the most appropriate answer from the options given below:

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UGC NET Paper 2: Electronic Science Nov 2020 Official Paper
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  1. (A), (C) only
  2. (A), (D) only
  3. (B), (D) only
  4. (B), (C) only

Answer (Detailed Solution Below)

Option 3 : (B), (D) only
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UGC NET Paper 1: Held on 21st August 2024 Shift 1
50 Qs. 100 Marks 60 Mins

Detailed Solution

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Concept:

The refractive index (η) is defined as:

 

c = speed of light in vacuum

v = speed of light in the medium

 

 

Phase velocity:

 

Calculation:

Taking ur = 1

Refractive Index will be:

 

Phase velocity will be:

 

= 1.22 × 108 m/s

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