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JEE Main 2005 (AIEEE) · Photoelectric Experiment: Intensity, Stopping Potential & Graphs

Photoelectric Experiment: Intensity, Stopping Potential & Graphs question from JEE Main 2005 (AIEEE)

Q78JEE Main 2005 · AIEEEEasy

Photoelectric Experiment: Intensity, Stopping Potential & Graphs

A photocell is illuminated by a small bright source placed 1 m1\ m away. When the same source of light is placed 12 m\frac{1}{2}\ m away, the number of electrons emitted by photo-cathode would

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Answer: (a)

  1. I∝1r2I \propto \frac{1}{r^2} and number of photoelectrons ∝I\propto I.
  2. r:1→12r: 1 \to \frac{1}{2} m ⇒I′=4I\Rightarrow I' = 4I.
  3. So the answer is (a) increases by a factor of 4.
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