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प्रश्न
Describe the principle of simple periscope through an outline ray diagram. Give one of its uses.
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उत्तर
Simple periscope is based upon the principle of reflection. It consists of cardboard or wooden tube, bent twice at right angles, and is provided with two openings as shown in the figure. Two plane mirrors are fixed at the bends of the tube at an angle 45° to the framework, such that the mirrors face each other. The tube is completely blackened from inside to avoid any reflection from its sides.
The parallel rays coming from an object at a higher plane, strike the plane mirror at an angle of 45° and hence are reflected through an angle of 45°.
These reflected rays strike the second mirror at an angle of 45° and hence are further reflected through an angle of 45°. These reflected rays on reaching the eye from the image on retina.
Use of periscope: It is used by soldiers in trench warfare.
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संबंधित प्रश्न
Fill in the blank
We are able to see the objects around us due to _________, reflection.
With the help of diagrams, explain the difference between the regular and irregular reflection.
What do you understand by the Light?
In the figure is shown a concave mirror. A is a point on the principal axis. If an object O is kept at A, image is formed on A itself. Copy the diagram. Draw the image in the diagram. Is the image real or virtual?
Measure the distance PA and write it in the diagram. What is the distance PA called?
Mark a point B on the principal axis, at which, if a point source of light is kept, the rays travel parallel to principal axis after reflection from M. What is point B called?
Complete the path of incident ray in the following case.
Match the following:
| 1. | Vegetable oil | a. | Transparent |
| 2. | Glass | b. | Translucent |
| 3. | Wood | c. | Waterproof |
| 4. | Aluminum foil | d. | Opaque |
An object that blocks all of the light from passing through is ______.
______ through which light can pass completely.
