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प्रश्न
State two uses of a concave mirror.
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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
An object of height 5 cm is placed perpendicular to the principal axis of a concave lens of focal length 10 cm. If the distance of the object from the optical centre of the lens is 20 cm, determine the position, nature and size of the image formed using the lens formula.
For what position of an object, a concave mirror forms a real image equal in size to the object?
Explain why, concave mirrors are used as shaving mirrors.
The angle of incidence for of light passing through the centre of curvature of a concave mirror is:
(a) 45°
(b) 90°
(c) 0°
(d) 180°
Giving reasons, state the 'signs' (positive or negative) which can be given to the following:
(a) object distance (u) for a concave mirror or convex mirror
(b) image distance (v) for a concave mirror
(c) image distance (v) for a convex mirror
A converging mirror forms a real image of height 4 cm of an object of height 1 cm placed 20 cm away from the mirror:
- Calculate the image distance.
- What is the focal length of the mirror?
Which of the following are concave mirrors and which convex mirrors?
A concave mirror cannot be used as:
(a) a magnifying mirror
(b) a torch reflector
(c) a dentist's mirror
(d) a real view mirror
Draw and complete the following diagrams to show what happens to the beams of light as they enter the glass block and then leave it:
Name the lens which can concentrate sun's rays to a point and burn a hole in a piece of paper.
