Question

4. State the law of reflection of light. If the speed
of light in vacuum is 3 x 10 8 m/s. find the speed of light in a medium of absolute refractive index 1.33
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Answer 1

Answer:

the laws of reflection of light

1) angle of incidence=angle of reflection

2) the reflected ray, incident ray and the normal lie on the same plane

Answer 2

Given :

• Speed of light in vacuum is 3 * 10^8 m/s
• Absolute refractive index is 1.33

To Find :

• Speed of light in medium

Solution :

We're given that the speed of light in vacuum is 3*10^8 m/s and the value of absolute refractive index is 1.33. Then we've to find Speed of light in medium.

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Use formula for refractive index :

⇒Refractive index = Speed of light in vacuum/Speed of light in medium

⇒μ = Speed of light in vacuum/Speed of light in medium

⇒μ = 3*10^8/Speed of light in medium

⇒Speed of light in medium = 3*10^8/μ

⇒Speed of light in medium = 3*10^8/1.33

⇒Speed of light in medium = 2.25 * 10^8

$\therefore$ Speed of light in medium is 2.25 * 10^8 m/s

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Laws of Reflection are :

• Angle of incidence is always equal to the angle of reflection.

• Incident ray , reflected ray and normal all lies on same plane.