Question

Which of the following options represent the variation of photoelectric current with the property of light shown on the x-axis? 

• A. A and C
• B. A and D
• C. B and D
• D. A only

Hint:

Remember the key laws of the photoelectric effect: 1. Photoelectric emission occurs only if the frequency of incident light is above a certain threshold frequency. 2. The photoelectric current is directly proportional to the intensity of incident light (for a frequency above the threshold). 3. The kinetic energy of the emitted photoelectrons depends on the frequency of incident light and is independent of the intensity.

Answer 1

The Correct Option is D

This problem concerns the relationship between photoelectric current and various light properties. Within the photoelectric effect, photoelectric current is primarily determined by two factors: light intensity and light frequency.

• Light Intensity: Photoelectric current exhibits a direct proportionality to the intensity of incident light. Increased intensity leads to a greater number of photons impacting the surface, consequently causing more electrons to be emitted, thereby generating a higher current, provided the frequency surpasses the threshold frequency.
• Light Frequency: For electron emission to occur, the frequency must exceed the material's threshold frequency. However, once this threshold is met, variations in frequency do not influence the current; instead, they impact the kinetic energy of the emitted electrons.

Applying these principles, the option 'A only' is deemed correct if it signifies the variation of photoelectric current with light intensity, assuming a constant frequency above the threshold. Consequently, the correct selection is A only.