Question

a object is placed near a concave mirror of focal length 15cm. the image so formed is real, inverted of size 1 cm an located 20 cm away from the mirror. determine the object position and it's size​

Answer 1

u=−15cm

f=−10cm

h=1cm

From mirror formula

f

1

=

u

1

+

v

1

v

1

=

f

1

−

u

1

v

1

=

−10

1

−

−15

1

v=−30cm

The image is formed at a distance 30cm on the left side of the mirror from the pole.

m=

h

h

′

=

u

−v

h

′

=−1×

−15

−30

h=−2cm

The image size is 2cm and it is real and inverted.