The power of the lens is +2.5D. What is the radius of the curvature?
2.5 cm
25.0 cm
40.0 cm
80.0 cm
Correct answer is D
The power of a lens is defined as the reciprocal of its focal length in metres:
P = \(\frac{100}{f}\) → 2.5 = \(\frac{100}{f}\)
where P is the power in diopters and f is the focal length in metres.
2.5 * f = 100
f = \(\frac{100}{2.5}\)
f = 40
Where f = \(\frac{r}{2}\)
radius of the curvature[r] = f * 2 → 40 * 2
r = 80cm