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प्रश्न
What happens when a light ray passes from a rarer medium to a denser medium?
विकल्प
It bends towards the normal.
It bends away from the normal.
It does not change its direction and hence does not refracted.
None of these
उत्तर
It bends towards the normal.
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संबंधित प्रश्न
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.
The absolute refractive indices of two media 'A' and 'B' are 2.0 and 1.5 respectively. If the speed of light in medium 'B' is 2 × 108 m/s, calculate the speed of light in:
(i) vacuum,
(ii) medium 'A'.
You are given kerosene, turpentine and water. In which of these does the light travel fastest? Use the information given in Table.
| 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 | 2.42 |
Which of the following diagrams shows the ray of light refracted correctly?
What name is given to the ratio of sine of angle of incidence to the sine of angle of refraction?
What is the unit of refractive index?
Which has higher refraction index : water of glass?
Refractive indices of carbon disulphide and ethyl alcohol are 1.63 and 1.36 respectively. Which is optically denser?
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.
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.
What is the speed of light in a medium of refractive index `6/5` if its speed in air is 3,00,000 km/s?
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.
What is meant by the refractive index of a substance?
Light travels through air at 300 million ms−1. On entering water it slows down to 225 million ms−1. Calculate the refractive index of water.
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 glass for light going from air to glass is .
The refractive index for light going from glass to air will be:
(a) `1/3`
(b) `4/5`
(c) `4/6`
(d) `5/2`
The speed of light in substance X is 1.25 × 108 m/s and that in air is 3 × 108 m/s. The refractive index of this substance will be:
(a) 2.4
(b) 0.4
(c) 4.2
(d) 3.75
The refractive indexes of four substances P, Q, R and S are 1.77, 1.50, 2.42 and 1.31 respectively. When light travelling in air is incident on these substances at equal angles, the angle of refraction will be the maximum in:
(a) substance P
(b) substance Q
(c) substance R
(d) substance S
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.
State the laws of refraction of light. Explain the term 'absolute refractive index of a medium' and write an expression to relate it with the speed of light in vacuum.
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?
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?
If the absolute refractive index of water is 1.36, find the speed of light in water. (Speed of light in vacuum = 3 × 108 m/s.)
Define the refractive index of a medium.
The refractive index of flint glass is 1.65 and that for alcohol is 1.36 with respect to air. What is the refractive index of the flint glass with respect to alcohol?
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 ______.
The velocity of light in a vacuum is 3 x 108 ms-1 and in glass is 2 x 108 ms-1. The refractive index of glass is ______.
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.
Absolute refractive indices of diamond and water are 2.42 and 1.33 respectively. Find the value of refractive index of water w.r.t. diamond.
