Question

a long sighted person has a minimum distance of distinct vision of 50 cm.he want to reduce it to 25 cm,which among the following.
convex lens of 25cm, convex lens of 50 cm.
,should he use?

Answer 1

The person is suffering from hypermetropia .

He use convex lens.

for focal length u=(-25cm)

v=(-50cm)

(lens formula)

1/f = 1/v -1/u

= (-1/50 - (-1/25)

= -1/50 + 1/25

1/f = 1/50

f = +50cm

p = 1/f

= 100/50

p = +2

plzz mark as brainliest answer !!!

Answer 2

u=-25 cm
v= -50cm
Using lens formula,
1/f=1v/-1/u
= (-1/50)+(1/25)
=(2-1/50)
=1/50
f=50 cm
He must use a convex lens of 50cm.