Question

if N number of identical lense,each of focal length f are placed in a contact such that all of them have a common principal axis, then the total power of this combination is N/F. true or false​

Answer 1

this is true .mark me as bainliest

Answer 2

The statement is true.

• The focal length of two lenses when both of them have a common principal axis and are placed in contact is
• $\frac{1}{f} = \frac{1}{f1} + \frac{1}{f2}$
• So if there are N lens, then the focal length of the combination will be F= f/N
• Power of a lens is the inverse of focal length.
• Therefore the power of combination of N lens will be N/f.