Question

A doctor has prescribed a corrective lens of power -1.5 D. Find the focal length of the lens. Is the
prescribed lens converging or diverging?

Answer 1

Answer:

f= -0.67m

Explanation:

P=1/f

-1.5=1/f

f=1/-1.5

f=(-10/15)

f= -2/3

f= -0.67m

Since the focal length is negative the lens used is concave.

HOPE THIS BRING A SMILE IN YOUR FACE

Answer 2

Answer:

Explanation:

P = -1.5 D

P = 1/f

f = 1/P = 1/(-1.5) = -0.67 m = -67 cm

Since focal length is negative, it is a diverging lens