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COMEDK202510 May 2025Evening ShiftPhysicsRay OpticsActual

What is the velocity of light in vacuum if the velocity of light in a medium of refractive index 1.2 is ' v ' ms ⁻¹ ?

Options

  1. A( v 1.2 ) m s⁻¹
  2. B(1.2 v) ms ⁻¹
  3. C3 10^8 m s⁻¹
  4. D(2.4 v) ms ⁻¹

Correct answer

B. (1.2 v) ms ⁻¹

Step-by-step solution

The refractive index of a medium is defined as the ratio of the speed of light in vacuum ( c ) to the speed of light in the medium ( v ). = c v Given that = 1.2 and the velocity in the medium is v , we have: 1.2 = c v Solving for c , the velocity of light in vacuum: c = 1.2 v Answer: (1.2 v) ms ⁻¹

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