Physics-
General
Easy
Question
An image of the sun is formed by a lens of focal length of 30 cm on the metal surface of a photoelectric cell and a photoelectric current I is produced. The lens forming the image is then replaced by another of the same diameter but of focal length 15 cm. The photoelectric current in this case is
- I
- 2I
- 4I
The correct answer is: 4I
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Þ 
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Þ
\
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