Dual Nature Of Light Question 270
Question: A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then [CBSE PMT 2003]
Options:
A) Number of electrons emitted is half the initial number
B) Each emitted electron carries half the initial energy
C) Number of electrons emitted is a quarter of the initial number
D) Each emitted electron carries one quarter of the initial energy
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Answer:
Correct Answer: C
Solution:
Number of electrons emitted $ \propto $ intensity $ \propto $ $ \frac{1}{{{(distance)}^{2}}} $
$ \Rightarrow \frac{n_{1}}{n_{2}}={{( \frac{d_{2}}{d_{1}} )}^{2}}=( \frac{2}{1} )=4 $
$ \Rightarrow ,n_{2}=\frac{n_{1}}{4} $
BETA
