The number of photo electrons emitted for light of a frequency

The number of photo electrons emitted for light of a frequency v (higher than the threshold frequency v₀) is proportional to:

1. Threshold frequency (v₀)
2. Intensity of light
3. Frequency of light (v)
4. v – v₀

The number of photoelectrons emitted is proportional to the intensity of incident light. Saturation current ∝ intensity.