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प्रश्न
Between which two points of concave mirror should an object be placed to obtain a magnification of:
(a) −3
(b) +25
(c) −0.4
उत्तर
(a) An object, in front of a concave mirror, should be placed between the latter's centre of curvature (C) and focus (F) to obtain a magnification of −3.
(b) An object, in front of a concave mirror, should be placed between the latter's focus (F) and the pole (P) to obtain a magnification of +25.
(c) An object, in front of a concave mirror, should be placed beyond the latter's centre of curvature (C) to obtain a magnification of −0.4.
संबंधित प्रश्न
If the image formed by a mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it? Draw a ray diagram to justify your answer. Where and why do we generally use this type of mirror?
The image of a candle flame placed at a distance of 30 cm from a mirror is formed on a screen placed in front of the mirror at a distance of 60 cm from its pole. What is the nature of the mirror? Find its focal length. If the height of the flame is 2.4 cm, find the height of its image. State whether the image formed is erect or inverted
Define (i) principal focus of a concave mirror, and (ii) focal length of a concave mirror.
Copy this figure in your answer book and show the direction of the light ray after reflection:
Explain why, a ray of light passing through the centre of curvature of a concave mirror gets reflected back along the same path.
According to the "New Cartesian Singh Convention" for mirrors, what sign has been given to the focal length of:
a concave mirror?
Which of the following are concave mirrors and which convex mirrors?
State two uses of a concave mirror.
Match the following.
| Convex mirror | Radio telescopes |
| Parobolic mirror | Rear – view mirror |
| Snell’s law | Kaleidoscope |
| Dispersion of light | sin i/sin r =μ |
| Refractive index | Rainbow |
Pick out the concave and convex mirrors from the following and tabulate them.
Rear-view mirror, Dentist’s mirror, Torchlight mirror, Mirrors in shopping malls, Make-up mirror.
