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प्रश्न
Why are concave mirrors used in solar devices?
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उत्तर
A concave mirror is also known as a converging mirror because of its ability to focus parallel rays of light at a single point on its focal plane. This property is used in solar devices. Parallel rays from the Sun, when reflected by the concave mirror, are focused at a particular point, generating a significant amount of heat. This heat is essential for the proper functioning of solar devices, such as solar cookers or solar furnaces.
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संबंधित प्रश्न
A spherical mirror and a thin spherical lens have each a focal length of -15 cm. The mirror and the lens are likely to be ______.
A concave mirror produces three times magnified image on a screen. If the object is placed 20 cm in front of the mirror, how far is the screen from the object.
If an object is placed at the focus of a concave mirror, where is the image formed?
If an object is at infinity (very large distance) in front of a concave mirror, where is the image formed?
Which mirror is used as a torch reflector? Draw a labelled diagram to show how a torch reflector can be used to produce a parallel beam of light. Where is the bulb placed in relation to the torch reflector?
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.
- Draw ray-diagrams to show the formation of images when the object is placed in front of a concave mirror (converging mirror):
- between its pole and focus
- between its centre of curvature and focus.
Describe the nature, size and position of the image formed in each case.
- State one use of concave mirror based on the formation of image as in case (i) above.
The focal length of a small concave mirror is 2.5 cm. In order to use this concave mirror as a dentist's mirror, the distance of tooth from the mirror should be:
(a) 2.5 cm
(b) 1.5 cm
(c) 4.5 cm
(d) 3.5 cm
An object is placed at a distance of 10 cm from a concave mirror of focal length 20 cm.
- Draw a ray diagram for the formation of image.
- Calculate the image distance.
- State two characteristics of the image formed.
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 produces three times enlarged virtual image of an object placed at 10 cm in front of it. Calculate the radius of curvature of the mirror.
An object is 24 cm away from a concave mirror and its image is 16 cm from the mirror. Find the focal length and radius of curvature of the mirror, and the magnification of the image.
If the image formed is always virtual, the mirror can be:
(a) concave or convex
(b) concave or plane
(c) convex or plane
(d) only convex
Name the lens which can concentrate sun's rays to a point and burn a hole in a piece of paper.
Draw a ray diagram to show the formation of the image of an object placed beyond the centre of curvature of a concave mirror. State the position, size and nature of the image.
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.
In which equipment/s do you find ___________________
Answer the following question:
An object is placed at a distance of 30 cm from a concave lens of focal length 30 cm.
(i) Use the lens formula to determine the distance of the image from the lens.
(ii) List four characteristics of the image (nature, position, size, erect/inverted) in this case.
(iii) Draw a labelled diagram to justify your answer of the part (ii)
______ is used as reflectors in torchlight.
The focal length of a concave mirror is 5cm. Its radius of curvature is ______.
