Question

A convergent lens of focal length 20 cm is in contact with a divergent lens of focal length 50 cm. The power of the combination is

Answer 1

Howdy!!

your answer is -----

we know that converging lens have positive focal length and diverging Lena have negative focal length .

so , power of converging lens is

= 1/20 = 0.05D

power is diverging lens is

= -1/50 = -0.02D


now, power of combination is ---
0.05 - 0.02 = 0.03D


hope it help you