A double-convex thin glass lens has equal-magnitude radii of curvature. The focal length of the Iens is $+ 37.3 \mathrm {~cm}$ and the index of refraction of the glass is $1.52$. What is the magnitude of the radius of curvature of each convex surface?
A) $31 \mathrm {~cm}$
B) $46 \mathrm {~cm}$
C) $35 \mathrm {~cm}$
D) $43 \mathrm {~cm}$
E) $39 \mathrm {~cm}$

Question

Quizplus · Accepted Answer

Using the lensmaker's equation: $ \frac{1}{f} = (n - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right) $, and given $ R_1 = R_2 = R $, we solve for $ R $ using $ f = 37.3 \, \text{cm} $ and $ n = 1.52 $. This results in $ R \approx 39 \, \text{cm} $.

A Double-Convex Thin Glass Lens Has Equal-Magnitude Radii of Curvature +37.3 cm+ 37.3 \mathrm {~cm}+37.3 cm

A Double-Convex Thin Glass Lens Has Equal-Magnitude Radii of Curvature $+ 37.3 \mathrm {~cm}$