Question

The power of a lens is $+2.0D$. Find its focal length and state the kind of the lens.

• A. Convex, $50cm$
• B. Convex, $200cm$
• C. Concave, $50cm$
• D. Concave, $100cm$

Answer 1

The correct option is A Convex, $50cm$

Since the power is positive, it is a convex lens.
$f=\frac{1}{P}=\frac{1}{2}=0.5m=50cm$