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प्रश्न
Rewrite the following statement by selecting the correct option:
If a ray of light strikes a glass slab at an angle of 600 with the surface of the slab, the angle of incidence must be __________________.
पर्याय
60°
30°
40°
120°
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उत्तर
If a ray of light strikes a glass slab at an angle of 600 with the surface of the slab, the angle of incidence must be 30°.
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संबंधित प्रश्न
In your laboratory you trace the path of light rays through a glass slab for different values of angle of incidence (∠i) and in each case measure the values of the corresponding angle of refraction (∠r) and angle of emergence (∠e). On the basis of your observations your correct conclusion is:
(a) ∠i is more than ∠r, but nearly equal to ∠e
(b) ∠i is less then ∠r, but nearly equal to ∠e
(c) ∠i is more than ∠e, but nearly equal to ∠r
(d) ∠i is less than ∠e, but nearly equal to ∠r
A student very cautiously traces the path of a ray through a glass slab for different values of the angle of incidence (∠i). He then measures the corresponding values of the angle of refraction (∠r) and the angle of emergence (∠e) for every value of the angle of incidence. On analysing these measurements of angles, his conclusion would be
(A) ∠i > ∠r > ∠e
(B) ∠i = ∠e > ∠r
(C) ∠i < ∠r < ∠e
(D) ∠i = ∠e < ∠r
State the dependence of angle of deviation On the refractive index of the material of the prism.
Draw the diagram given below and clearly show the path taken by the emergent ray.
A ray of light passes from water to air. How does the speed of light change?
Which colour of light travels fastest in any medium except air?
Observe the following figure and answer the questions given under it:
1) How many times does refraction take place in the above figure?
2) What happens to the ray of light when it passes from air to glass?
3) What happens to the ray of light when it passes from glass to air?
4) What are the rays AB and CD in the figure called?
5) Define refraction.
How can you bend light away from the normal?
How must light travel out of a substance if it is not going to be refracted?
How is the refractive index of a medium related to the speed of light in it?
A light ray in passing from water to a medium
(a) speeds up
(b) slows down. In each case, give one example of the medium.
A ray of light is passing from a transparent medium 1 to another transparent medium 2 (i) Speed up (ii) slows down. In each case, state whether the refractive index of medium 2 is equal to, less than or greater than the refractive index of medium 1.
Fill in the blanks to complete the following sentence
When light travels from a denser to a rarer medium, its speed ……………….
How is the angle of emergence related to the angle of incidence when prism is in the position of minimum deviation? Illustrate your answer with help of a labelled diagram using an equilateral prism?
A Water pond appears to be 2.7 m deep. If the refractive index of water is 4/3, find the actual depth of the pond.
A ray of light enters a glass slab ABDC as shown in figure and strikes at the centre O of the circular part AC of the slab. The critical angle of glass is 42°. Complete the path of the ray till it emerges out from the slab. Mark the angles in the diagram wherever necessary.
A student has traced the path of a ray of light through a glass slab as follows. If you are asked to label 1, 2, 3 and 4, the correct sequencing of labeling ∠i, ∠e, ∠r and lateral displacement respectively is
(a) 2, 1, 3, 4
(b) 1, 2, 3, 4
(c) 1, 3, 2, 4
(d) 1, 3, 4, 2
In the fig., PO is a ray of light incident on a rectangular glass block.
(a) Complete the path of the ray through the block.
(b) In the diagram, mark the angle of incidence (i) and the angle of refraction (r) at the first interface. How is the refractive index of glass related to the angles I and r?
(c) Mark angle of emergence by the letter e. How are the angles i and e related?
(d) Which two rays are parallel to each other? Name them.
(e) Indicate in the diagram the lateral displacement between the emergent ray and the incident ray.
Which colour of light travels fastest in any medium except air?
How does the deviation produced by a prism depend on the refraction index of its material.
Name the phenomenon responsible in the following case:
Apparent bending of a stick in water
A fish swimming in a pond seems nearer than it really is. Explain.
State the factors on which the angle of deviation depends.
State the relation between the refractive index μ and the velocity of light (vm) in that medium.
What is the total reflecting prism?
Name two instruments of the total refracting prism in which is used.
What do you understand by the deviation produced by a prism?
After a robbery, if a window has been broken, there will be tiny particles of glass. Some of these will be found at the scene of the crime and some may be caught in the thief’s clothing. If the police can prove that these particles are identical, they have a strong case.
A method of doing this is to suspend the particles of glass in a special liquid. Light of a single colour is thrown through the liquid and the particles viewed through a microscope. The temperature of the liquid is then slowly altered. This alters the speed of light through the liquid (i.e., it alters the refractive index). At one particular temperature, the particles of glass disappear. It this happens at the same temperature for both sets of glass particles, they probably came from the same broken pane of glass.
Complete and copy the diagram to show how light bends when it travels from the liquid to the glass and back to the liquid, If the light slows down in the glass.
How will you verify the laws of refraction or how the refractive index of glass is determined in the laboratory?
Trace a ray of light incident at 30° on a surface if travelling from air to glass. What is the angle of refraction in this case? (R.I. for glass = 3/2).
A ray of light PQ is incident normally on the hypotenuse of a right-angled prism ABC as shown in the diagram given below:
(i) Copy the diagram and complete the path of the ray PQ till it emerges from the prism.
(ii) What is the value of the angle of deviation of the ray?
(iii) Name an instrument where this action of the prism is used.
Draw the ray diagram of a glass slab having medium A and B for the velocity of light ray VA and VB respectively and define Snell's law.
- If VB = 1.5 VA, then which medium is denser?
- What is the refractive index of A with respect to B?
- What is the refractive index of B with respect to A?
