Question

When an object is placed at a distance of 50 cm from a concave spherical mirror ,the magnification produced is, -1/2 . Where should the object be placed to get a magnification of, -1/5 .

Answer 1

Object should be placed at-125cm because :-
m=-v/u m is given -1/2 and u=50cm so putting in we get
-1/2=-v/50
50/2=v
25=v
Now putting the value of v in next case
m=-v/u here we have v= 25 m=-1/5
m=-v/u
-1/5=-25/u
u=5×25=125
u=-125