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प्रश्न
The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch?
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उत्तर
The beam of light from the torch will be diffused with lower intensity due to the rusted reflecting surface.
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संबंधित प्रश्न
An object is placed at a distance of 12 cm in front of a concave mirror of radius of curvature 30 cm. List four characteristics of the image formed by the mirror.
If the focal length of a convex mirror is 25 cm, what is its radius of curvature?
Fill in the following blank with suitable word:
Parallel rays of light are reflected by a concave mirror to a point called the ..........
Copy this figure in your answer book and show the direction of the light ray after reflection:
An object is placed at a distance of 10 cm from a concave mirror of focal length 20 cm.
- Draw a ray diagram for the formation of image.
- Calculate the image distance.
- State two characteristics of the image formed.
Draw a ray diagram to show the formation of image of an object placed on the principal axis of a convex mirror. State the position, size and nature of the image. What happens to the image as the object is moved away from the mirror?
Draw the ray diagram and also state the position, the relative size and the nature of image formed by a concave mirror when the object is placed at the centre of curvature of the mirror.
You are provided with a concave mirror, a convex mirror, a concave lens and a convex lens. To obtain an enlarged image of an object you can use either
______ mirrors make things look larger when objects are placed close to them.
A student took three concave mirrors of different focal lengths and performed the experiment to see the image formation by placing an object at different distance with these mirrors as shown in the following table.
| Case No. | Object-distance | Focal length |
| I | 45 cm | 20 cm |
| II | 30 cm | 15 cm |
| III | 20 cm | 30 cm |
Now answer the following questions:
(a) List two properties of the image formed in Case I.
(b) In which one of the cases given in the table, the mirror will form real image of same size and why?
(c) Name the type of mirror used by dentists. Given reason why do they use such type of mirrors.
OR
(c) Look at the table and identify the situation (object distance and focal length) which resembles the situation in which concave mirrors are used as shaving mirrors? Draw a ray diagram to show the image formation in this case.
