An equiconvex lens is cut into two halves along `(i) XOX^(')` and `(ii) YOY^(')` as shown in the figure. Let `f,f^(')f^('')` be the focal lengths of the complete lens, of each half in case `(i)`, and of each half in case `(ii)`, respectively
Choose the correct statement from the following

Options

A. `f^(')=f, f^('')=2f`
B. `f^(')=2f, f^('')=f`
C. `f^(')=f, f^('')=f`
D. `f^(')=2f, f^('')=2f`

Answer

A

Explanation

In the first case, neither the radii of curvature not the material of the lens is affected. ltbr. In the second case,
`(1)/(f^(''))(mu-1)((1)/(R) )`
or `(1)/(f^(2))=(1)/(2)(mu_-1)((2)/(R))=(1)/(2f)` or `f^('')=2f`.