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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
A student has obtained the image of a distant object with a concave mirror to determine its focal length. If he has selected a well-illuminated red building as object, which of the following correctly describes the features of the image formed?
(A) Virtual, inverted and diminished image in red shade
(B) Real, erect and diminished image in pink shade
(C) Real, inverted and diminished image in red shade
(D) Virtual, erect and enlarged image in red shade
State where an object must be placed so that the image formed by a concave mirror is:
(b) at infinity.
(c) the same size as the object.
A concave mirror has a focal length of 25 cm. At which of the following distance should a person hold his face from this concave mirror so that it may act as a shaving mirror?
(a) 45 cm
(b) 20 cm
(c) 25 cm
(d) 30 cm
Give reason for your choice.
At what distance from a concave mirror focal length 10 cm should an object 2 cm long be placed in order to get an erect image 6 cm tall?
A concave mirror has a focal length of 4 cm and an object 2 cm tall is placed 9 cm away from it. Find the nature, position and size of the image formed.
______ is used as reflectors in torchlight.
Large ______ mirrors are used to concentrate sunlight to produce heat in solar furnaces.
Beams of light are incident through the holes A and B and emerge out of box through the holes C and D respectively as shown in the figure. Which of the following could be inside the box?
An object at a distance of 30 cm from a
concave mirror gets its image at the same point. The focal length of the mirror is ______.
An erect and enlarged image can be formed by
