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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
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.
Draw a ray diagram to show the path of the refracted ray in each of the following cases:-
A ray of light incident on a concave lens is
(i) passing through its optical centre.
(ii) parallel to its principal axis.
(iii) directed towards its principal focus.
It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm.
What should be the range of distance of an object placed in front of the mirror?
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°
Fill in the following blank with suitable word:
Parallel rays of light are reflected by a concave mirror to a point called the ..........
Fill in the following blank with suitable word:
A concave mirror .......... rays of light whereas convex mirror ............ rays
What is the minimum number of rays required for locating the image formed by a concave mirror for an object? Draw a ray diagram to show the formation of a virtual image by a concave mirror.
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
What is the position of the image when an object is placed at a distance of 20 cm from a concave mirror of focal length 20 cm?
An object is placed at a distance of 10 cm from a concave mirror of focal length 20 cm.
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.
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.
How can a concave mirror be used to obtain a virtual image of an object? Draw a diagram to illustrate your answer.
Draw the ray diagram and also state the position, the relative size and the nature of image formed by a concave mirror when the object is placed at the centre of curvature of the mirror.
A _____________ mirror is used by a dentist.
In which of the following, the image of an object placed at infinity will be highly diminished and point sized?
Which of the following mirror is used by a dentist to examine a small cavity in a patient’s teeth?
An image formed by a lens is erect. Such an image could be formed by a
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
In torches, searchlights, and headlights of vehicles, the bulb is placed ______ of the concave mirror.
