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प्रश्न
State whether the following statement is true or false:
Refraction occurs because light slows down in denser materials.
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उत्तर
True.
The refraction of light is due to the change in the speed of light on going from one medium to other. The speed of light ray slows down in denser materials.
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संबंधित प्रश्न
What is lateral inversion? Explain by giving a suitable example.
An extended object in the form of an arrow pointing upward has been placed in front of a plane mirror. Draw a labelled ray-diagram to show the formation of its image.
What is meant by 'reflection of light'?
With the help of a labelled ray-diagram, describe how a plane mirror forms an image of a point source of light placed in front of it. State the characteristics of the image formed in a plane mirror.
The figure given alongside shows the image of a clock as seen a plane mirror. The correct time is:
Figure
(a) 2.25
(b) 2.35
(c) 6.45
(d) 9.25
A man sits in an optician's chair looking into plane mirror which is 2 m away from him and views the image of a chart which faces the mirror and is 50 cm behind his head. How far away from his eyes does the chart appear to be?
If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it?
Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.
Draw a diagram showing the refraction of a light ray from water to glass. Label on it the incident ray, the angle of incidence (/), and the angle of refraction (r)
The phenomenon of change in the direction of light when it passes from one transparent medium to another is called ___________.
Due to _______ pencil looks bent in water, in the given experiment.
Lights of different colours are used as signal for safety transport. From these, the wavelength of red light is _______ nm.
Light changes its direction when going from one transparent medium to another transparent medium. This is called _______.
Write scientific reason.
The bottom of a pond appears raised.
Numerical problems.
The speed of light in water is 2.25 × 108 ms–1. If the speed of light in vacuum is 3 × 108 ms–1, calculate the refractive index of water.
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.
Her friend noted the following observations from this demonstration:
- Glass is optically rarer than air.
- Air and glass allow light to pass through them with the same velocity.
- Air is optically rarer than glass.
- Speed of light through a denser medium is faster than that of a rarer medium.
- The ratio: sin of angle of incidence in the first medium to the ratio of sin of angle of refraction in the second medium, gives the refractive index of the second material with respect to the first one.
Which one of the combinations of the above statements given below is correct.
A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the pencil appear to be bent to the same extent, if instead of water we use liquids like, kerosene or turpentine. Support your answer with reason.
Which object use the reflection of light?
Under what circumstances there won’t be any refraction of light when it enters from one medium to another?
