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Holding the frequency of the incident light fixed, the saturation photocurrent in a photoelectric circuit is found to be directly proportional to
Athe wavelength of the incident light
Bthe intensity of the incident light
Cthe work function of the emitter metal
Dthe square root of the applied accelerating voltage
Answer & Solution
Correct answer: B. the intensity of the incident light
1. NCERT §11.4.1 reports the experimental result: with $\nu$ and the accelerating potential held fixed, photocurrent rises LINEARLY with intensity.
2. The microscopic reason: a brighter source delivers MORE photons per second; each absorbed photon ejects one electron (when above threshold).
3. So the number of photoelectrons per second is proportional to intensity, and so is the saturation current.
4. Wavelength (A) affects per-photon energy, not how many photons land. Work function (C) affects threshold, not slope above threshold. Accelerating voltage (D) only affects whether all emitted electrons are collected, not how many are emitted.
_Source: NCERT Class 12 Physics Part 2, Ch 11, §11.4.1 "Effect of intensity of light on photocurrent", p. 4._
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