Question

An object of height 10 cm is placed before a convex mirror of focal length 250 cm. If the height of image is 5 cm the object distance is
(A) 2.5 m
(B) 1 m
(C) 1.5 m
(D) 0.5 m

Answer 1

Answer:

Object distance u=−36 cm

Focal length of concave mirror f=−12 cm

Using mirror formula :

v

1

+

u

1

=

f

1

Or

v

1

+

−36

1

=

−12

1

⟹ v=−18 cm

Magnification

h

o

h

i

=

u

−v

Or

10

h

i

=

−10

−(−18)

⟹ h

i

=−18 cm