Question

two lens 1&2 are placed in contact . focal length of lens 1 is 20cm and 2 is 10cm .calculate : a)total power of combination b)what is the nature of combination

Answer 1

Answer:here

F1= 20*10^-2 m

F2= 10*10^-2m

Then

For total power after the combination,

1/F = 1/F1 + 1/ F2

P= 15 dioptres

Nature of combination:: since the power obtained is positive , the image formed is real

Explanation: