Question

where should the object be placed to get a magnification of -1/5 object distance 50cm​

Answer 1

Distance of object from the mirror u=−50 cm

Distance of image from the mirror v=−10 cm

For lens, we know

f

1

=

v

1

−

u

1

f

1

=

−10

1

−

−50

1

f=−12.5cm

It is a concave lens.