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प्रश्न
Give one use each of a concave and a convex mirror.
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उत्तर
- Concave mirror: Concave mirrors can form an enlarged image of an object. Therefore, dentists use them to see the enlarged image of the patient’s teeth.
- Convex mirror: A convex mirror forms a diminished and upright image of an object. It is used as a side view mirror of the car because it enables the driver to view objects spread over a large area behind him/her.
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संबंधित प्रश्न
A 4 cm tall object is placed on the principal axis of a convex lens. The distance of the object from the optical centre of the lens is 12 cm and its sharp image is formed at a distance of 24 cm from it on a screen on the other side of the lens. If the object is now moved a little away from the lens, in which way (towards the lens or away from the lens) will he have to move the screen to get a sharp image of the object on it again? How will the magnification of the image be affected?
A student obtained on a screen the sharp image of a candle flame placed at the farther end of laboratory table using a concave mirror. For getting better value of focal length of the mirror, the teacher suggested to him to focus the sun. What should the student do?
(A) Should move the mirror away from the screen.
(B) Should move the mirror towards the screen.
(C) Should move the mirror and screen both towards the sun.
(D) Should move only the screen towards the sun.
Define the terms focus and focal length of a concave mirror. Draw diagram to illustrate your answer.
The image formed by a convex mirror is
A real and enlarged image can be obtained by using a
Draw a ray diagram in each of the following cases to show the formation of image, when the object is placed :
(i) between the optical centre and principal focus of a convex lens.
(ii) anywhere in front of a concave lens.
(iii) at 2F of a convex lens.
State the signs and values of magnifications in the above-mentioned cases (i) and (ii).
Define the following term in relation to concave mirror.
Radius of curvature
The following Figure shows a concave mirror MM' on which a ray of light incident from a point P gets reflected to meet the principle axis at O.
(a) Find, by construction, the position of the centre of curvature of the concave mirror.
(b) Write down the value for the radius of curvature of the mirror.
(c) Calculate the focal length of the mirror.
(d ) Which relation is used in deducing the focal length from the radius of curvature?
The image formed in a plane mirror is always inverted.
