A concave mirror forms a real image with |m|=2. If object-image separation is 25 cm, find |f| in centimetres.
Physics · Geometrical optics · spherical mirror
JEE Mains NEET

Question

A concave mirror forms a real image with |m|=2. If object-image separation is 25 cm, find |f| in centimetres.

G1 Physics · Accepted Answer

v=2u and v−u=u=25 cm. Thus f=uv/(u+v)=50/3≈16.67 cm.