Question

Photoelectric current does not depend on which of the following

• A. the velocity of light
• B. the nature of the emitter material
• C. the intensity of incident light
• D. the potential difference applied between the two electrodes

Answer 1

Answer: (A)

the velocity of light

Answer 2

The photoelectric effect describes the emission of electrons when light shines on a material. The photoelectric current is the flow of these emitted electrons.

1. Intensity of incident light: The number of photoelectrons emitted per second is directly proportional to the intensity of the incident light (provided the frequency is above the threshold frequency).

2. Nature of the emitter material: Different materials have different work functions, which is the minimum energy required to eject an electron.

3. Potential difference applied between the two electrodes: Applying a positive potential to the anode attracts the emitted photoelectrons, increasing the current until it reaches a saturation value.

4. Velocity of light: The velocity of light in a vacuum ($c \approx 3 \times 10^8$ m/s) is a fundamental physical constant. The photoelectric effect depends on the energy of the individual photons (determined by their frequency or wavelength) and the number of photons (intensity), not on the variability of the speed of light.