Question

the equi- convex lens shown in figure has a focal length f. what will be the focal length of each half of the lens is cut along AB

Answer 1

Answer:

focal length of each half of the lens is cut along AB is 2f

Explanation:

As we know by the Lens makers formula that focal length of the lens is given by

$\frac{1}{f} = (\mu - 1)(\frac{1}{R_1} - \frac{1}{R_2})$

$\frac{1}{f} = (\mu - 1)(\frac{1}{R} + \frac{1}{R})$

$f = \frac{R}{2(\mu - 1)}$

now when lens is cut along the line shown in the figure

now we have

$\frac{1}{f'} = (\mu - 1)(\frac{1}{R} + 0)$

so we have

$f' = \frac{R}{\mu - 1}$

so the focal length becomes double of the initial value

so we have

$f' = 2f$

#Learn

Topic : Lens Makers Formula

https://brainly.in/question/6624327