Question

A thin convex lens whose focal length in air is known to be 30 cm is cut into two parts

Answer 1

⭐⭐⭐ Hey mate!!⭐⭐⭐

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⚡⚡Answer:- f'=2f

Explanation:-

⭐If equiconvex lens is cut perpendicular to the principal axis.

Then,

Initial focal length

♐Consider u = mu = refrective index

❄️f = R /2(u-1).....(1)

Focal length after cutting....

f'=R/(u-1)........(2)

❄️Dividing equation 1 and 2 yiu will get

❄️f/f'= 1/2

❄️f'=2f

Hence,

Focal length becomes double to that of initial.❄️

Hope it will help you...✌️✌️

#phoenix⭐