Correct Answer - Option 3 : decreased by
\(\frac{1}{16}\) times
The correct answer is option 3) i.e. decreased by \(\frac{1}{16}\) times
CONCEPT:
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Photocell: A photocell is used as a resistor that varies its resistance when light is incident on it. The energy of photons of incident light causes the emission of electrons thereby, decreasing the resistance.
- It converts light energy into electrical energy.
- It works on the principle of the photoelectric effect.
The intensity of ejected electrons in a photocell (n) depends on its distance from the source of light (d) as follows:
n ∝ \(\frac{1}{d^2}\)
EXPLANATION:
The number of ejected electrons when the distance between the source and photocell is 1 m,
\(N = \frac{1}{1^2} = 1\)
The number of ejected electrons when the distance between the source and photocell is 4 m,
\(N' = \frac{1}{4^2} = \frac{1}{16} = \frac{N}{16}\)
Therefore, the number of electrons ejected will be decreased by \(\frac{1}{16}\) times.
