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प्रश्न
Fill in the blank and Explain the completed sentences.
Refractive index depends on the ______ of light.
उत्तर
Refractive index depends on the velocity of light.
Explanation:
- Refractive index depends on the velocity of light in the medium.
- As light has different velocity in the different medium refractive index also changes.
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संबंधित प्रश्न
How refraction of light is related to refractive index?
The velocity of light in a medium is 1.5 x 108 m/s. What is the refractive index of the medium with respect to air, if the velocity in air is 3 x 108 m/s?
The refractive indices of glass and water with respect to air are 3/2 and 4/3 respectively. If speed of light in glass is 2 x 108 m/s, find the speed of light in water.
If the refractive index of glass for light going from air to glass is 3/2, find the refractive index of air for light going from glass to air.
Find out, from Table, the medium having highest optical density. Also find the medium with lowest optical density.
| Material medium | Refractive index | Material medium | Refractive index |
| Air | 1.0003 | Canada Balsam | 1.53 |
| Ice | 1.31 | – | – |
| Water | 1.33 | Rock salt | 1.54 |
| Alcohol | 1.36 | – | – |
| Kerosene | 1.44 | Carbon disulphide | 1.63 |
| Fused quartz | 1.46 | Dense flint glass | 1.65 |
| Turpentine oil | 1.47 | Ruby | 1.71 |
| Benzene | 1.50 | Sapphire | 1.77 |
| Crown glass | 1.52 | Diamond | .42 |
What is the unit of refractive index?
Fill in the following blank with a suitable word:
When a ray of light goes from air into a clear material, you see the ray bend. How much the ray bends is determined by the ............... of the material.
Give three examples of materials that refract light rays. What happens to the speed of light rays when they enter these materials?
Define Snell's law of refraction. A ray of light is incident on a glass slab at an angle of incidence of 60°. If the angle of refraction be 32.7°, calculate the refractive index of glass. (Given : sin 60° = 0.866, and sin 32.7° = 0.540).
The speed of light in water is 2.25 × 108 m/s. If the speed of light in vacuum be 3 × 108 m/s, calculate the refractive index of water.
Light enters from air into diamond which has a refractive index of 2.42. Calculate the speed of light in diamond. The speed of light in air is 3.0 × 108 ms−1.
The refractive indices of four substance P, Q, R and S are 1.50, 1.36, 1.77 and 1.31 respectively. The speed of light is the maximum in the substance:
(a) P
(b) Q
(c) R
(d) S
The refractive index of water is:
(a) 1.33
(b) 1.50
(c) 2.42
(d) 1.36
The following table gives the refractive indices of a few media:
| 1 | 2 | 3 | 4 | 5 | |
| Medium | Water | Crown glass | Rock salt | Ruby | Diamond |
| Refractive index | 1.33 | 1.52 | 1.54 | 1.71 | 2.42 |
Use this table to give an example of:
(i) a medium pair so that light speeds up when it goes from one of these medium to another.
(ii) a medium pair so that light slows down when it goes from one of these medium to another.
Define the term absolute refractive index. The absolute refractive index of diamond is 2.42. What is the meaning of this statement? Refractive indices of media A, B C and D are given below:
|
Media |
Refractive index |
|
A |
1.33 |
|
B |
1.44 |
|
C |
1.52 |
|
D |
1.65 |
In which of these four media is the speed of light (i) minimum and (ii) maximum ?
Find the refractive index of medium C with respect to medium B.
State the law of refraction of light that defines the refractive index of a medium with respect to the other. Express it mathematically. How is refractive index of any medium 'A' with respect to a medium 'B' related to the speed of propagation of light in two media A and B? State the name of this constant when one medium is vacuum or air.
The refractive indices of glass and water with respect to vacuum are 3/2 and 4/3 respectively. If the speed of light in glass is 2 × 108m/s, find the speed of light in (i) vacuum, (ii) water.
Mark the correct answer in the question.
If the refractive index of glass with respect to air is 3/2, what is the refractive index of air with respect to glass?
If in a medium, the speed of light is 1.5 × 108 m/s how much will the absolute refractive index of that medium be?
Light travels with a velocity 1.5 x 108 m/s in a medium. On entering second medium its velocity becomes 0.75 x 108 m/s. What is the refractive index of the second medium with respect to the first medium?
The velocity of light in a medium is 1.5 x 188 m/s. What is the refractive index of the medium with respect to air, if the velocity in the air is 3 x 108 m/s?
2n1 : Refractive index of medium 2 with respect to medium 1 : : 1n2 : _______
Purple has the lowest refractive index.
Solve the following example.
Speed in first medium, v1 = 3 × 108 m/s
Speed in second medium, v2 = 2 × 108 m/s
Then 2n1 = ?
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 ______.
Light travel fastest in ______.
Noor, a young student, was trying to demonstrate some properties of light in her Science project work. She kept ‘X’ inside the box (as shown in the figure) and with the help of a laser pointer made light rays pass through the holes on one side of the box. She had a small butter-paper screen to see the spots of light being cast as they emerged.
If the object inside the box was made of a material with a refractive index less than 1.5 then the ______.
Refractive index of diamond with respect to glass is 1.6 and absolute refractive index of glass is 1.5. Find out the absolute refractive index of diamond.
Match the Columns:
| Column ‘A’ | Column ‘B’ |
| Refractive index of water | (a) 1.31 |
| (b) 1.36 | |
| (c) 1.33 |
How is the refractive index of material related to the velocity of light?
Match the pair:
| Group 'A' | Group 'B' | |
| Substance | Refractive index | |
| Air | (a) | 1.33 |
| (b) | 1.46 | |
| (c) | 1.0003 |
A light ray enters from medium A to medium B as shown in the figure.
Which one of the two media is denser w.r.t. other medium? Justify your answer.
- Explain why the refractive index of any material with respect to air is always greater 1.
- In the figure below a light ray travels from air into the semi-circular plastic block. Give a reason why the ray does not deviate at the semi-circular boundary of the plastic block.
- Complete the ray diagram of the above scenario when the light ray comes out of the plastic block from the top flat end.
