Question

the focal length of the combination of two thin lenses in contact is 80 cm.If the focal length of one lens is -20cm ,what is the power of other lens?​

Answer 1

Answer:

focal length of other lens is 16 cm and it's power is 0.0625

Answer 2

Answer:1 D

Explanation:f1 + f2 =80cm

f1 =-20cm

So,f2=80+20=100cm=1m

Power of 2nd lens= 1/1=1D