Question

Calculate the power of a convex lens of focal length 12.5 cm.

Answer 1

\[ \text{Applying, } \mathrm{P} = \frac{100}{f \text{(in cm)}}  \]

\[= \frac{100}{12.5}\]

= +8D

Thus, power is +8D. The positive sign shows that lens is convex.