Question

Find the focal length and nature of lens

which should be placed in contact with a

lens of focal

length 10 cm so that the power of the

combination becomes 5 dioptre.
Plz tell​

Answer 1

Please refer this image...

Hope this helps you!!

Answer 2

Answer:

The second lens to be used is a concave lens or converging lens having power -5 dioptre and focal length -0.2m or -20 cm