Step 1: Conceptual Foundation:
This query pertains to the photoelectric effect laws. Light intensity correlates with the photon flux incident on a surface per unit area per unit time. Photoelectric current arises from the movement of ejected photoelectrons.
Step 2: Detailed Analysis:
Within the quantum framework of light, radiation intensity is directly proportional to the number of photons incident per second. The photoelectric effect operates on a one-to-one basis: a single incident photon ejects a single electron, provided the photon's energy meets or exceeds the threshold energy (i.e., its frequency is above the threshold frequency).
Consequently:
- Increased intensity signifies a greater photon flux impinging on the surface each second.
- A higher photon flux results in more photoelectrons being ejected per second.
- An elevated rate of photoelectron ejection translates to a larger charge flow, constituting a greater photoelectric current.
This establishes a direct proportionality:
Intensity of incident radiation \(\propto\) Number of photons per second \(\propto\) Number of photoelectrons emitted per second \(\propto\) Photoelectric current.
Let's assess the given options based on this understanding:
1. Incorrect. The quantity of photoelectrons is contingent on the photon count (intensity), not the individual photon's energy (frequency).
2. Incorrect. The relationship is direct, not inverse.
3. Correct. As elucidated, the rate of photoelectron emission per second is directly proportional to the intensity of the incident radiation.
4. Incorrect. A direct and fundamental relationship exists.
Step 3: Conclusion:
The proportionality of the photoelectric current to the number of photoelectrons emitted per second indicates that this emission rate is directly proportional to the intensity of the incident radiation.