Question

The maximum kinetic energy of photoelectrons depends on:

• A. Intensity of light
• B. Frequency of light
• C. Time of exposure
• D. Distance from source

Hint:

Keep these distinct: Intensity controls the 'amount' (photoelectric current).
Frequency controls the 'energy' (maximum kinetic energy and stopping potential).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The photoelectric effect is the emission of electrons from a material when light shines upon it.
The properties of these emitted electrons (photoelectrons) are governed by the quantum nature of light.

Step 2: Key Formula or Approach:
Einstein's photoelectric equation is the key to solving this: \( K_{\text{max}} = h\nu - \Phi \).
Here, \( K_{\text{max}} \) is the maximum kinetic energy, \( h \) is Planck's constant, \( \nu \) is the frequency of incident light, and \( \Phi \) is the work function of the material.

Step 3: Detailed Explanation:
According to the photoelectric equation, \( K_{\text{max}} \) is directly dependent on the frequency \( \nu \) of the incident light.
If the frequency of the light increases, the energy of the incident photons increases, resulting in a higher maximum kinetic energy for the emitted electrons.
The intensity of light determines the number of photons striking the surface per unit time.
Increasing intensity increases the number of emitted photoelectrons but does not change the maximum kinetic energy of an individual electron.
Time of exposure and distance from the source only affect the total number of photons arriving over time, not their individual energy.

Step 4: Final Answer:
The maximum kinetic energy of photoelectrons depends entirely on the frequency of light.