JEE Advanced · Physics · 24. Ray Optics
Sunlight of intensity is incident normally on a thin convex lens of focal length . Ignore the energy loss of light due to the lens and assume that the lens aperture size is much smaller than its focal length. The average intensity of light, in , at a distance from the lens on the other side is __________.
- A 130
- B 135
- C 140
- D 145
Answer & Solution
Correct Answer
(A) 130
Step-by-step Solution
Detailed explanation
Ratio of area
Let energy incident on lens be E
Given
Also
\(\therefore\) Average intensity of light at \(22 cm=\frac{E}{a}=\frac{A \times 1.3}{a}=100 \times 1.3\) \(=130 kW / m ^2\)
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