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प्रश्न
State two uses of a concave mirror.
उत्तर
Two uses of concave mirror are :
- Concave mirror is used as REFLECTOR in headlights of cars and in searchlight. The source of light (bulb) is placed at the principal focus and the reflector forms a parallel beam of light.
- For doctors to examine throat, ear, nose and eyes, light is focused with the help of a concave mirror.
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संबंधित प्रश्न
List four characteristics of the images formed by plane mirrors.
A communications satellite in orbit sends a parallel beam of signals down to earth. If these signals obey the same laws of reflection as light and are to be focussed onto a small receiving aerial, what should be the best shape of the metal 'dish' used to collect them?
Draw ray-diagrams to show the formation of images when the object is places in front of a concave mirror (converging mirror):
(i) between its pole and focus
(ii) between its centre of curvature and focus
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(a) concave mirror as well as concave lens
(b) convex mirror as well as concave lens
(c) concave mirror as well as convex lens
(d) concave mirror as well as convex lens
A student has to trace the path of a ray of light passing through a rectangular glass slab for four different values of angle of incidence.
(a) Write two important precautions for this experiment.
(b) List two conclusions the student will draw based on his experiment.
Choose the correct option from given alternative:
Consider the following properties of virtual images:
(A) cannot be projected on the screen
(B) are formed by both concave and convex lens
(C) are always erect
(D) are always inverted
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 |
Large ______ mirrors are used to concentrate sunlight to produce heat in solar furnaces.
A student wants to obtain an erect image of an object using a concave mirror of 10 cm focal length. What will be the distance of the object from mirror?
Which type of mirror is used in the following?
Head lamps of a car
