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प्रश्न
Why does obtaining the image of the sun on paper with the help of a concave mirror burn the paper?
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उत्तर
The rays from the Sun are parallel. When these rays fall on the concave mirror, they converge to a single point on the focal plane of the mirror. Thus, a lot of heat is produced at that point. Now, if a paper is placed at that point to get the image of the Sun, the paper gets burnt because of the huge amount of heat concentrated at that point.
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संबंधित प्रश्न
Draw a ray diagram for concave mirror when the object is between centre of curvature and focus.
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 ______.
The angle between an incident ray and the plane mirror is 30°. The total angle between the incident ray and reflected ray will be:
(a) 30°
(b) 60°
(c) 90°
(d) 120°
Find the focal length of a concave mirror whose radius of curvature is 32 cm.
The image formed by a concave mirror is real, inverted and highly diminished (much smaller than the object). The object must be:
(a) between pole and focus
(b) at focus
(c) at the centre of curvature
(d) at infinity
According to the "New Cartesian Singh Convention" for mirrors, what sign has been given to the focal length of:
a concave mirror?
An object is placed at a distance of 10 cm from a concave mirror of focal length 20 cm.
Calculate the image distance.
A large concave mirror has a radius of curvature of 1.5 m. A person stands 10 m in front of the mirror. Where is the person's image?
An object is placed at a large distance in front of a concave mirror of radius of curvature 40 cm. The image will be formed in front of the mirror at a distance:
(a) 20 cm
(b) 30 cm
(c) 40 cm
(d) 50 cm
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
An object is placed 15 cm from (a) a converging mirror, and (b) a diverging mirror, of radius of curvature 20 cm. Calculate the image position and magnification in each case.
With the help of a labelled diagram, explain how a concave lens diverges a beam of parallel light rays. Mark the principal axis, optical centre, principal focus and focal length of the concave lens on the diagram.
Large ______ mirrors are used to concentrate sunlight to produce heat in solar furnaces.
Which of the following can make a parallel beam of light when light from a point source is incident on it?
A child is standing in front of a magic mirror. She finds the image of her head bigger, the middle portion of her body of the same size and that of the legs smaller. The following is the order of combinations for the magic mirror from the top.
State whether the following statement is True or False.
The sides of an object and its image formed by a concave mirror are always interchanged
The ENT doctor uses a ______.
In the headlights of motor vehicles, ______ mirrors are used as reflectors.
______ mirrors make things look larger when objects are placed close to them.
