Question

Define power of a lens. What is its unit? One student uses a lens of power +2.0 D
and another uses a lens of power-2.5 D what type of lenses are used by each
student
​

Answer 1

Answer:

The degree of divergence or convergence achieved by a given lens is called power of the lens.

The unit of power of lens is diopter and is expressed by D.

Focal length of lens used by first student is in positive hence it is a convex lens. The lens of second student is a concave lens.

p=

f

1

=

0.5

1

=2

Power of lens (first student) =+2

Power of lens (second student) =−2