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प्रश्न
The refractive indices of water and glass with respect to air are 4/3 and 3/2 respectively. If the speed of light in glass is 2 × 108ms−1, find the speed of light in (i) air, (ii) water.
उत्तर
Given: Refractive index of water, nw = 4/3 and Refractive index of glass, ng = 3/2
Speed of light in glass, vg = 2×108 m/s
(i)
`n_g/n_a="v"_a/"v"_g` where, `n_a` = refractive index of air = 1
`"v"_a` = speed of light in air
`therefore "v"_a=n_g/n_axx"v"_g=(3/2)/1xx(2xx10^8)=3xx10^8`m/s
(ii)
`n_g/n_w="v"_w/"v"_g`,where, `"v"_w`= speed of light in water
`therefore"v"_w=n_g/n_wxx"v"_g=(3/2)/(4/3)xx(2xx10^8)=2.25xx10^8` m/s
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संबंधित प्रश्न
The speed of light in air is:
(a) 3 × 108 cm/s
(b) 3 × 108 mm/s
(c) 3 × 108 km/s
(d) 3 × 108 m/s
What name is given to the ratio of sine of angle of incidence to the sine of angle of refraction?
The refractive index of diamond is 2.42. What is the meaning of this statement in relation to the speed of light?
The speed of light in vacuum and in two different glasses is given in the table below:
| Medium | Speed of light |
| Vacuum | 3.00 × 108 m/s |
| Flint glass | 1.86 × 108 m/s |
| Crown glass | 1.97 × 108 m/s |
(a) Calculate the absolute refractive indexes of flint glass and crown glass.
(b) Calculate the relative refractive index for light going from crown glass to flint glass.
The speed of light in air is 3 × 108 m/s. In medium X its speed is 2 × 108 m/s and in medium Y the speed of light is 2.5 × 108 m/s Calculate:
(a) air nx
(b) air nY
(c) x nY
The refractive index of water is:
(a) 1.33
(b) 1.50
(c) 2.42
(d) 1.36
The refractive index of water with respect to air is `4/3`. The refractive index of air with respect to water will be:
(a) 1.75
(b) 0.50
(c) 0.75
(d) 0.25
Solve the following example.
Speed in first medium, v1 = 3 × 108 m/s
Speed in second medium, v2 = 2 × 108 m/s
Then 2n1 = ?
Define the refractive index of a medium.
A light ray enters from medium A to medium B as shown in figure. The refractive index of medium B relative to A will be ______.
