Question

For fixed values of radii of curvature of lens, power of the lens will be ____.
Fill in the blank with the correct answer from the options given below

• A. $P \propto (\mu - 1)$
• B. $P \propto \mu^2$
• C. $P \propto \frac{1}{\mu}$
• D. $P \propto \mu^{-2}$

Answer 1

Answer: (A)

$P \propto (\mu - 1)$

Answer 2

The power P of a lens is related to the refractive index $μ$ and the radii of curvature $R_1$ and $R_2$ by the Lensmaker’s formula:
$P = (\mu - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right)$
For fixed values of the radii of curvature $R_1$ and $R_2$, the power of the lens is directly proportional to $μ − 1$.