Q139 / 200 · NEET 2022 (Phase 1) · Physics

A biconvex lens has radii of curvature $20 cm$ each. If the refractive index of the material of the lens is $1.5$ , the power of the lens is:

A
$+ 20 D$
Correct answer
B
$+ 5 D$
C
infinity
D
$+ 2 D$

Solution

Power of the lens is,

$P = \frac{1}{f} = (μ - 1) (\frac{1}{R_{1}} - \frac{1}{R_{2}}) \Rightarrow P = (1.5 - 1) (\frac{1}{0.2} - \frac{1}{- 0.2}) = 0.5 \times 10 \Rightarrow P = + 5 D$

Hence, the correct answer is option: 'B'.

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A biconvex lens has radii of curvature 20 cm each. If the refractive index of the material of the lens is 1.5, the power of the lens is:

Solution

Relevant Questions

A biconvex lens has radii of curvature $20 cm$ each. If the refractive index of the material of the lens is $1.5$ , the power of the lens is: