Question

at what distance from a concave mirror of focal length 10 cm should be placed so that its real image is formed 20 cm from the mirror? ​

Answer 1

Answer:

f= 10cm

v= 20cm

so using mirror formula

1/f= 1/V - 1/u

so, 1/u= 1/f - 1/v

1/u = 1/10 - 1/20

=- 0.05