Question

The photo current in a photo diode depends on:

• A. Applied electric field
• B. Frequency of the incident light
• C. Wavelength of incident light
• D. Intensity of incident light

Hint:

For the photoelectric effect, remember that: - The energy of the emitted electrons depends on the frequency of the incident light. - The intensity of the light determines the number of emitted electrons but not their energy.

Answer 1

The Correct Option is B

Step 1: Understanding the photoelectric effect.
The photo current in a photo diode is primarily influenced by the frequency of the incident light. According to the photoelectric effect, when light of a certain frequency strikes a metal surface, electrons are emitted, creating a photo current. The intensity of the light affects the number of emitted electrons, while the frequency determines if the electrons will have enough energy to be emitted at all.
Step 2: Answer Justification.
The frequency of the incident light is the critical factor that determines the emission of electrons. If the frequency is below a certain threshold, no current is generated, regardless of the light's intensity. This is why the correct answer is option (2).