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संबंधित प्रश्न
A 4 cm tall object is placed on the principal axis of a convex lens. The distance of the object from the optical centre of the lens is 12 cm and its sharp image is formed at a distance of 24 cm from it on a screen on the other side of the lens. If the object is now moved a little away from the lens, in which way (towards the lens or away from the lens) will he have to move the screen to get a sharp image of the object on it again? How will the magnification of the image be affected?
Explain the following term related to spherical lenses: focal length
A concave mirror always forms a real image.
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. |
What is the relation between the focal length and radius of curvature of a spherical mirror (concave mirror of convex mirror)? Calculate the focal length of a spherical mirror whose radius of curvature is 25 cm.
What is meant by magnification? Write its expression. What is its sign for the (a) real (b) virtual, image?
Define the following term in relation to concave mirror.
Center of curvature
Define the term Pole.
Define focal length.
What is the focal length (f) of a mirror?
