Question

35. If your eye glasses have focal length 50 cm what is your near point?

Answer 1

Answer:

The near point of a hypermetropic person is 50 cm from the eye. What is the power of the lens required to enable the person to read clearly a book held at 25 cm from the eye? Focal length, f = ? Hence, the corrective lens is convex because, power of the lens is positive.

Answer 2

Answer:

Let the near Points be 25 cm

So,

f = 50cm

Now,

1/v -1/u = 1/f

=>1/v +1/25cm = 1/50cm

=>1/v = 1/50cm -1/25cm

=>1/v = -1/50cm

=>v = -50/1 cm ≈ -50 cm

Hope it will be helpful :)