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प्रश्न
A coin placed at the bottom of a vessel appears to be raised when water is poured in the vessel.
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उत्तर
The coin at a appears to be at B i. e. depth of coin observed is less than the actual depth at A.
The ray of light starting from A (denser) medium bends away from the normal. Due to the Refraction of light, the coin appears at B at a lower depth. Hence, in the same way, the depth of water appears to be less deep.
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संबंधित प्रश्न
One half of a convex lens of focal length 10 cm is covered with a black paper. Can such a lens produce an image of a complete object placed at a distance of 30 cm from the lens? Draw a ray diagram to justify your answer. A 4 cm tall object is placed perpendicular to its principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 15 cm. Find the nature, position and the size of the image.
An image that cannot be obtained on a screen is called ______.
Match the items given in Column I with one or more items of Column II.
| Column I | Column II | ||
| (a) | A plane mirror | (i) | Used as a magnifying glass. |
| (b) | A convex mirror | (ii) | Can form image of objects spread over a large area. |
| (c) | A convex lens | (iii) | Used by dentists to see enlarged image of teeth. |
| (d) | A concave mirror | (iv) | The image is always inverted and magnified. |
| (e) | A concave lens | (v) | The image is erect and of the same size as the object. |
| (vi) | The image is erect and smaller in size than the object. |
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
What name is given to the distance between spherical mirror and carbon paper?
Which are the two convenient rays that are chosen to construct the image by a spherical mirror for a given object? Explain with the help of suitable ray diagrams.
State the kind of mirror used
(a) by a dentist, and
(b) as a street light reflector.
How will you distinguish between a plane mirror, a concave mirror and a convex mirror, without touching them?
Numerical problem.
The radius of curvature of a spherical mirror is 25 cm. Find its focal length.
