Question

When an object io placed at a distance of 50 cm from a concave spherical mirror the magnification produce is_1\2; where should the object b e placed to get a magnification of,_1\5?

Answer 1

u= 50cm

-v/u = -1/2

Cross multiply

u= -2×v

50= -2×v

50/-2 = v

v= 25cm

Now,

New magnification = -v/u = -1/5

Cross multiply -25/u = -1/5

-u = 5 × -25

-u = -125

Therefore, u= 125cm.