REFLECTION OF LIGHT
A concave mirror forms a sharp image of a distant tree. What name is given to the distance between the
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1 concave mirror and screen on which sharp image is formed?
2 In what condition, the image formed by a concave mirror is virtual? 1
3 Specified the size of image formed by a concave mirror when m > 1. 1
4 What is the position of the object placed on the side of reflecting surface of a concave mirror of focal length 15
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cm if the image is formed at the distance of 30 cm from the mirror?
5 Which mirror, concave or convex always converges the light rays? 1
The image of an object formed by a mirror is real, inverted and is of magnification –1. If the image is at a
distance of 40 cm from the mirror, where is the object placed? Where would the image be if the object is
6 moved 20 cm towards the mirror? State reason and also draw ray diagram for the new position of the object 3
to justify your answer.
7 A spherical mirror produces an image of magnification –1 on a screen placed at a distance of 50 cm from the
mirror.
(a) Write the type of mirror.
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(b) Find the distance of the image from the object.
(c) What is the focal length of the mirror?
(d) Draw the ray diagram to show the image formation in this case.
8 A student wants to obtain an erect image of an object using a concave mirror of 12 cm focal length. What
should be the range of distance of the object from the mirror? State the nature and size of the image he is 3
likely to observe. Draw a ray diagram to justify your answer.
9 For the given data showing the focal lengths of three concave mirrors A, B and C, and the respective distances
of different objects from these mirrors.
Object distance Focal length
S.No.
(cm) (cm)
A 45 20 3
B 30 15
C 20 30
Answer the following questions:
(i) In the given position of object from the mirrors, which mirror will form a diminished image of the object.
Draw a ray diagram for image formation by this mirror.
(ii) Which mirror can be conveniently used as a make-up mirror? Draw a ray diagram to illustrate this function.
10 If the image formed by mirror for all positions of the object placed in front of it is always virtual and
diminished, state the type of the mirror. Draw a ray diagram in support of your answer. Where are such
mirrors commonly used and why?
(a) Define the following terms in the context of spherical mirrors:
(i) Pole (ii) Centre of curvature (iii) Principal axis (iv) Principal focus
11 (b) Draw ray diagrams to show the principal focus of a (i) concave mirror (ii) convex mirror
(c) Consider the following diagram in which M is a mirror and P is an object and Q is its magnified image
formed by the mirror. State the type of the
mirror M and one characteristic property of the image Q.
12 It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm.
(i) What should be the range of distance of an object placed in front of the mirror?
(ii) Will the image be smaller or larger than the object? Draw ray diagram to show the formation of image in
this case. 5
(iii) Where will the image of this object be, if it is placed 24 cm in front of the mirror? Draw ray diagram for
this situation also to justify your answer.
Show the positions of pole, principal focus and the centre of curvature in the above ray diagrams.
13 A student has focussed the image of a candle flame on a white screen using a concave mirror. The situation is
as given below:
Length of the flame = 1.5 cm
Focal length of the mirror = 12 cm
Distance of flame from the mirror = 18 cm
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If the flame is perpendicular to the principal axis of the mirror, then calculate the following:
(a) Distance of the image from the mirror
(b) Length of the image.
If the distance between the mirror and the flame is reduced to 10 cm, then what would be observed on the
screen? Draw ray diagram to justify your answer for this situation.
