Question

An object is placed at a distance of 10 cm in front of a convex mirror and image is formed at a distance of 15 cm from the mirror.Find focal length of the mirror.​

Answer 1

Answer:

ANSWER

It is to be remembered that a convex mirror always forms the virtual, erect and diminished image.

Given: Object distance, u=−10cm Focal length, f=15cm

To find: Image distance, v

From mirror formula :

v

1

+

u

1

=

f

1

v

1

−

10

1

=

15

1

v

1

=

15

1

+

10

1

=

150

25

v=6cm

Hence image will be formed 6 cm beyond the mirror, i.e virtual magnification

m=

u

−v

=

−10

−6

=0.6

Answer 2

Explanation:

distance at which the object is placed=10cm

image formed=15cm

focal length=I/2*radius

=1/2*7.5

7.5/2cm is the answer