Question

In photoelectric emission, the value of the saturation current depends on:

• A. the frequency of incident light.
• B. the work function of the surface.
• C. the intensity of incident light.
• D. the anode potential.

Hint:

Saturation current counts electrons emitted per second, and each photon frees one electron, so think about what controls the photon count.

Answer 1

The Correct Option is C

Step 1: Separate "how many" from "how energetic".
Photoelectric results split into two families: quantities that fix the electron count (current) and quantities that fix the electron energy (stopping potential). Saturation current belongs to the first family.

Step 2: Use the one-photon-one-electron rule.
Photoemission is a one-to-one photon-electron event. Doubling the light intensity means twice as many photons per second hit the plate, so roughly twice as many electrons are released per second, doubling the saturation current. Hence \(I_{sat}\) tracks intensity directly.

Step 3: Test each distractor.
Frequency changes the energy each electron carries away, shifting the stopping potential but not the count. Work function only sets the threshold frequency for emission. Anode potential merely collects the electrons; once all of them are collected the current saturates and extra voltage does nothing.

Step 4: Pick the answer.
Only the intensity governs the saturation current, so statement (iii) is right.

\[\boxed{\text{Intensity of incident light}}\]