The kinetic energy of the photoelectrons depends upon the

Options

A. (a) Intensity of striking light
B. (b) Number of photons striking
C. (c) Frequcncy of striking light
D. (d) Number of photonselectrons ejected

Answer

To determine how the kinetic energy of photoelectrons depends on various factors, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Photoelectric Effect**:
- The photoelectric effect occurs when light (photons) strikes a metal surface and ejects electrons from that surface.

2. **Einstein's Photoelectric Equation**:
- According to Einstein's photoelectric equation, the kinetic energy (KE) of the emitted photoelectrons can be expressed as:
\[ KE = h\nu - \phi \]
where:
- \( KE \) is the kinetic energy of the photoelectron,
- \( h \) is Planck's constant,
- \( \nu \) is the frequency of the incident light,
- \( \phi \) (phi) is the work function of the metal (the minimum energy required to eject an electron).

3. **Analyzing the Equation**:
- From the equation, we can see that the kinetic energy of the photoelectrons is directly related to the frequency of the incident light.
- The work function (\( \phi \)) is a constant for a given metal and does not change with the frequency of light.

4. **Effect of Frequency**:
- If the frequency of the incident light (\( \nu \)) increases, the kinetic energy of the emitted photoelectrons also increases, provided that the frequency is above the threshold frequency (\( \nu_0 \)), which is the minimum frequency needed to eject an electron.

5. **Effect of Intensity**:
- The intensity of the light affects the number of photons striking the surface and thus the number of photoelectrons ejected, but it does not affect the kinetic energy of the individual photoelectrons.
- Therefore, increasing the intensity (which increases the number of photons) does not increase the kinetic energy of the emitted electrons.

6. **Conclusion**:
- The kinetic energy of the photoelectrons depends solely on the frequency of the incident light and not on the intensity or the number of photons or photoelectrons.

### Final Answer:
The kinetic energy of the photoelectrons depends upon the **frequency of the striking light**.