Jee Advanced
Geometrical Optics
IIT-JEE 2010 Paper 1 Offline
INTEGER+3 / -02010
The focal length of a thin biconvex lens is 20 cm. When an object is moved from a distance of 25 cm in front of it to 50 cm, the magnification of its image changes from m25 to m50. The ratio \({{{m_{25}}} \over {{m_{50}}}}\) is __________.