Question

Power of a convex lens of focal length 50 cm is ___.

• A. -2D
• B. -0.5D
• C. +2D
• D. +0.5D

Answer 1

The correct option is C +2D

Let $P$ be the power of the lens and $f$ be its focal length.
Given, $f=50cm$
$P=\frac{100}{f\left(cm\right)}=\frac{100}{50}=2D$