Question

A converging lens has a focal length of 50 cm The power of the lens is:

• A. $+5D$
• B. $+2D$
• C. $+0.5D$
• D. $-0.5D$
• E. $-2D$

Answer 1

Answer: (B)

Power of a lens is inverse of focal length (in metres) $P=\frac{1}{f}$ Given, $f=50cm$ $\therefore$ $P=\frac{100}{50}=+2D$