The kinetic energy of the photoelectrons depends upon the

Options

A. Intensity of striking light
B. Number of photons striking
C. Frequency of striking light
D. Number of photoelectrons ejected

Answer

To solve the question regarding the dependence of the kinetic energy of photoelectrons, we can break it down into a step-by-step explanation.

### Step 1: Understand the Photoelectric Effect
The photoelectric effect describes the phenomenon where electrons are ejected from a material (usually a metal) when it is exposed to light of sufficient frequency.

**Hint:** Remember that the photoelectric effect is a key concept in quantum mechanics and relates to how light interacts with matter.

### Step 2: Identify the Key Formula
The kinetic energy (KE) of the emitted photoelectrons can be expressed using the equation:
\[ KE_{\text{max}} = h\nu - h\nu_0 \]
Where:
- \( KE_{\text{max}} \) is the maximum kinetic energy of the photoelectrons.
- \( h \) is Planck's constant.
- \( \nu \) is the frequency of the incident light.
- \( \nu_0 \) is the threshold frequency of the material.

**Hint:** Focus on the terms in the equation and how they relate to each other.

### Step 3: Analyze the Components
From the equation, we can see that:
- The term \( h\nu \) represents the energy of the incoming photons.
- The term \( h\nu_0 \) represents the minimum energy required to eject an electron from the material.

**Hint:** Consider how changing the frequency of the incoming light affects the kinetic energy of the emitted electrons.

### Step 4: Determine the Dependence on Frequency
The kinetic energy of the photoelectrons is directly proportional to the frequency of the incident light (\( \nu \)). As the frequency increases, the kinetic energy of the emitted electrons increases, provided that the frequency is above the threshold frequency (\( \nu_0 \)).

**Hint:** Think about what happens when you increase the frequency of the light while keeping the intensity constant.

### Step 5: Evaluate Other Factors
- **Intensity of Light:** The intensity of light relates to the number of photons striking the surface, but it does not affect the energy of each individual photon. Therefore, it does not directly influence the kinetic energy of the photoelectrons.
- **Number of Photons:** While the number of photons can affect how many electrons are ejected, it does not change the kinetic energy of the individual photoelectrons.
- **Threshold Frequency:** This is a fixed property of the material and does not change with the light source.

**Hint:** Differentiate between factors that affect the number of emitted electrons versus those that affect their kinetic energy.

### Conclusion
The kinetic energy of the photoelectrons primarily depends on the frequency of the incident light. Therefore, the correct answer is that the kinetic energy of the photoelectrons depends on the frequency of the striking light.

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