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प्रश्न
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.
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उत्तर
An expression for heat produced in a conductor by using Joule's experiment:
1) Refraction occurs twice, once at Point N and the second time at Point M.
2) Air is rarer than glass. So, when light passes from the rarer medium to the denser medium, it bends towards the normal.
3) When light passes from the denser (glass) medium to the rarer (air) medium, it bends away from the normal.
4) Ray AB is called the incident ray, and ray CD is called the emergent ray.
5) Refraction of light is the phenomenon of change in the direction of propagation of light when it passes obliquely from one transparent medium to another.
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संबंधित प्रश्न
When a ray of light travels from air to glass slab and strikes the surface of separation at 90°, then it …………….
(a) bends towards normal
(b) bends away from normal
(c) passes unbent
(d) passes in zigzag way
What is a spectrum?
If the speed of light in vacuum is 3 × 108 ms−1, find the speed of light in a medium of absolute refractive index 1.5.
On the basis of the experiment, "To trace the path of a ray of light through a rectangular glass slab", students of a class arrived at which one of the following conclusions?
(A) Angle of incidence is greater than the angle of emergence.
(B) Angle of emergence is smaller than the angle of refraction.
(C) Emergent ray is parallel to the refracted ray.
(D) Incident ray and emergent ray are parallel to each other.
State the dependence of angle of deviation On the wavelength of light
Name one factor that affects the lateral displacement of light as it passes through a rectangular glass slab.
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?
The following diagram shows a 60°, 30°, 90° glass prism of critical angle 42°, Copy the diagram and complete the path of incident ray AB emerging out of the prism marking the angle of incidence on each surface.
A ray of light strikes the surface of a rectangular glass block such that the angle of incidence in
air is 0°.
In each case, draw diagram to show the path taken by the ray as it passes through the glass block and emerges from it.
What do you understand by the statement the refractive index of glass is 1.5 for white light?
Fill in the blanks to complete the following sentence
When light travels from a denser to a rarer medium, its speed ……………….
Fill in the blanks to complete the following sentence
The refractive index of glass with respect to air is 3/2. The refractive index of air with respect to glass will be ……………….
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 postage stamp kept below a rectangular glass block of refractive index 1.5 when viewed from vertically above it, appears to be raised by 7.0 mm. Calculate the thickness of the glass slab.
A ray of light OP passes through a right angles prism as shown in the adjacent diagram.
(a) State the angles of incidence at the faces AC and BC.
(b) Name the phenomenon which the ray suffers at the face AC.
Four students A, B, C and D traced the paths of incident ray and the emergent ray by fixing pins P and Q for incident ray and pins R and S for emergent ray for a ray of light passing through a glass slab.
The correct emergent ray was traced by the student:
(1) A
(2) B
(3) C
(4) D
Observe the figure and write accurate conclusion regarding refraction of light.
A ray of light passes from air to water. In fig. 39, which of the ray A, B, C and D is the correct refracted ray?
Fig shows a lens as a combination of a glass block and two prisms.
(i) Name the lens formed by the combination.
(ii) What is the line XX' called?
(iii) Complete the path of the incident ray PQ after passing through the lens.
(iv) The final emergent ray either meets XX' at a point or appears to come from a point on XX'. Label it as F, What is this point called?
Using the curve, how do you infer that for given prism, the angle of minimum deviation δmin is unique for the given light?
A total reflecting equilateral prism can be used to deviate a ray of light through:
Choose the correct alternative and rewrite the following:
A glass slab is placed in the path of convergent light. The point of convergence of light
Name the phenomenon responsible in the following case:
Apparent bending of a stick in water
Why is the colour red used as a sign of danger?
Can the absolute refractive index of a medium be less than one?
The figure shows two prisms A and B. A monochromatic ray of light PO is incident at the face of the prism A. Complete the diagram to show the path of the ray till it emerges out of the prism B.
The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.
(a) Does the light speed up or slow down in the glass,
(b) Give the reason for your answer.
Trace a ray of light incident at 30° on a surface if travelling from glass to air. What is the angle of refraction in this case? (R.I. for glass = 3/2).
Calculate the velocity of light in a glass block of refractive index 1.5. (Velocity of light in air = 3 × 108 m/s)
The velocity of light in diamond is 121000 kms-1. What is its refractive index?
Observe the figure and name the ray AB, ray CD, ray GH.
Which colour of white light travels fastest in any medium except air?
