Question

43. An object of height 2 cm is placed at a distance of 16cm from a concave mirror. The
mirror forms a real image of height 3em. Calculate position of image formed and the focal
length of the mirror.
​

Answer 1

Answer:

Here h

1

= 2 cm, u = -16 cm, h

2

= -3 cm (Since image is real and inverted.)

∵m=

h

1

h

2

=−

u

v

∴v=

h

1

−h

2

u=

2

3

×(−16)=−24cm

f

1

=

v

1

+

u

1

=−

24

1

−

16

1

=

48

−2−3

=

48

−5

;f=

5

−48

=−9.6cm