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प्रश्न
What is mirage? Give a reason for its formation?
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उत्तर
Hot sand (Rarer medium)
MIRAGE: When it is very hot, an inverted image of a tree is seen which is ‘illusion of eye’ (gives a false impression) of water under the tree. This is called a MIRAGE.”
REASON: Sand becomes very hot during hot noon, the layers of air in contact become rarer (expand) while upper layers of air are still at comparatively low temperature and are denser medium.
When rays of light from DENSER to RARER medium (starting from tree) are bent away from normal when refracted from Rarer to Denser medium (going towards the eye) bend towards normal and a tree appears INVERTED.
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संबंधित प्रश्न
Rays of light incident parallel to the principal axis pass through the focus after reflection from a concave mirror.
Describe an experiment to show that a light ray bends when it passes from one transparent medium into another transparent medium.
Define the following terms :
Incident ray, Refracted ray, Angle of incidence, Angle of refraction.
The diagram in figure shows a ray of light AO falling on a rectangular glass slab PQRS. Complete the diagram till the ray of light emerges out of the slab. Label on the diagram the incident ray, the refracted ray and the emergent ray.
Say TRUE or FALSE
The image formed in a pinhole camera is always inverted
Figure shows a pencil placed above a mirror
- Draw its image formed by the mirror
- Show how light rays from the object are reflected at the mirror to form the image for the eye.
A boy of height 1m 45 cm is standing in front of a long mirror at a distance of 2 m. From this information, fill up the following sentences:
- The distance between the boy and his image is ______
- The height of the image is______
- When the boy moves 1m forward, the distance between her and her image is______
Assertion (A): Virtual objects can’t be seen by the human eye.
Reason (R): Virtual image is formed by converging rays.
A real image is inverted and can be caught on the screen.
Describe the nature of images formed by plane mirrors.
