Question

Two thin converging lenses of focal length 10cm and 15cm respectively are held in contact with each other. Calculate full power and focal length ofcombination.

Answer 1

Focal lenght=10cm= 0.1m

Focal length =15cm=o.15m

P= 1/f+ 1/f

P=1/0.1+1/0.15

P= 16.6D

F=1/P

F=1/16.6 = 0.06m