Reflections of
light
1. A 5 cm tall object is
placed perpendicular to
the principal axis of a
convex lens of focal-
length 20 cm. The
distance of the object from
the lens is 30 cm. Find the:
(i) position
(ii) nature
(iii) size of the image
formed.
2. (a) Write two rules of
the new Cartesian sign
conventions for spherical
mirrors.
(b) Trace the path of the
reflected ray by drawing a
figure if it passes from
centre of curvature of a
concave mirror.
3. 4.5 cm needle is placed
12 cm away from a convex
mirror of focal length 15
cm. Give the location of
image and magnification.
Describe what happens to
the image as the needle is
moved farther from the
mirror.
4. Rohit placed a pencil
perpendicular to principal
axis in front of a
converging mirror of focal
length 30 cm. The image
formed is twice the size of
the pencil. Calculate the
distance of the object from
the mirror.
5.The image of a candle
flame placed at a distance
of 30 cm from a mirror is
formed on a screen placed
in front of the mirror at a
distance of 60 cm from its
pole. What is the nature of
the mirror? Find its focal
length. If the height of the
flame is 2.4 cm, find the
height of its image. State
whether the image formed
is erect or inverted. An
object is placed at a
distance of 25 cm away
from a converging mirror
of focal length 20 cm.
Discus the effect on the
nature and position of the
image if the position of the
object changes from 25
cm to 15 cm. Justify your
answer without using
mirror formula.
6. Which kind of mirror is
used in the headlights of a
car? Why is it used for this
purpose?
7. 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.
8. If an object is placed at
a distance of 8cm from a
concave mirror of focal
length 10cm, discuss the
nature of the image
formed by drawing the ray
diagram.
9. An object placed 20 cm
in front of a mirror is found
to form an image of 15 cm
(i) in front of it, (ii) behind
the mirror. Find the focal
length of the mirror and
the kind of mirror in each
case.
10. An object is placed at
a distance of 10 cm from a
concave mirror of focal
length 20 cm .
(i) Draw a ray diagram for
the formation of image.
(ii) Calculate the image
distance.
(iii) State two
characteristics of the
image formed.
11.An arrow 2.5 cm high is
placed at a distance of 25
cm from a diverging mirror
of focal length 20 cm. Find
the nature, position and
size of the image formed.
12.A converging mirror
forms a real image of
height 4 cm of an object of
height 1 cm placed 20 cm
away from the mirror.
Calculate (i) image
distance, (ii) focal length of
the mirror.
13. Why do we prefer a
convex mirror as a rear-
view mirror in vehicles?
14. A concave mirror
produces three times
magnified (enlarged) real
image of an object placed
at 10 cm in front of it.
Where is the image
located?
15. The image of a candle
flame placed at a distance
of 30 cm from a mirror is
formed on a screen placed
in front of the mirror at a
distance of 60 cm from its
pole. What is the nature of
the mirror? Find its focal
length. If the height of the
flame is 2.4 cm, find the
height of its image. State
whether the image formed
is erect or inverted.
