A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
Answer
Given
Power of lens = +1.5 D
We know that,
Power of the lens = 1/Focal length
1.5 = 1/Focal Length
Focal length = 1/1.5
Focal length = 10/15
Focal length = 2/3
Focal length = +0.67 m
Since the focal length is positive, the lens is a convex lens.
And convex lens are converging lens
Hence, the prescribed lens is converging.
