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प्रश्न
Numerical problem.
Light enters from air into a glass plate having refractive index 1.5. What is the speed of light in glass? (Ans: 2 × 108 ms–1)
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उत्तर
Given: Refractive index (µ) = 1.5
Speed of light in vacuum (c) = 2 × 108ms– 1
Speed of light in glass (υ) = ?
Solution:
µ= `"Speed of light in vacuum (c)"/"Speed of light in glass (υ)"`
1.5 = `(2×10^8"ms"^(-1))/"υ" ⇒ "υ" = (2×10^8"ms"^(-1))/1.5= 1.3 × 10^8 "ms"^(-1)`
∴ Speed of light in glass = `1.3 × 10^8 "ms"^(-1)`
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संबंधित प्रश्न
State whether light slows down or speeds up in the following cases :
Light going from air to glass.
State whether light slows down or speeds up in the following cases :
Light going from water to air.
A light ray passes from water to
- air, and
- glass.
In each case, state how does the speed of light change.
The speed of light in air is 3 × 108 m s-1. Calculate the speed of light in glass. The refractive index of glass is 1.5.
What is the speed of light in vacuum?
Higher Order Thinking Skills.
Light ray emerges from water into air. Draw a ray diagram indicating the change in its path in water.
Light travels ______ kilometers per second in air or vacuum. In theory, nothing can travel faster than light.
Materials that allow light to pass through completely are known as ______ material.
Materials that allow light to pass through completely are known as transparent materials.
Define opaque material.
