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प्रश्न
Explain the working of a periscope.
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उत्तर
Periscope:
- It is an instrument used for viewing bodies or ships, which are over and around another body or a submarine.
- It is based on the principle of the law of reflection of light.
- It consists of a long outer case and inside this case mirrors or prisms are kept at each end, inclined at an angle of 45°.
- Light coming from the distant body falls on the mirror at the top end of the periscope and gets reflected vertically downward.
- This light is reflected again by the second mirror kept at the bottom, so as to travel horizontally and reach the eye of the observer.
- In some complex periscopes, optic fiber is used instead of mirrors for obtaining a higher resolution.
- The distance between the mirrors also varies depending on the purpose of using
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संबंधित प्रश्न
Where is the image when you look at something in a mirror?
State and explain the laws of reflection of light at a plane surface (like a plane mirror), With the help of a labelled ray-diagram. Mark the angles of 'incidence' and 'reflection' clearly on the diagram. If the angle of reflection is 47.5°, what will be the angle of incidence?
The angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
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In which material do you think light rays travel faster-glass or air?
Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.
The diagram (figure) given below shows two parallel rays 1 and 2 incident on (a) a concave mirror, (b) a convex mirror. Draw the reflected rays and mark the focus by the symbol F.
Fill in the blank and Explain the completed sentences.
The change in ______ of light rays while going from one medium to another is called refraction.
Observe the given figure and write appropriate phenomenon of light in the box.
