The photoelectric effect can be explained on the basis of

Options

A. Corpuscular theory
B. Wave theory
C. electromagnetic theory
D. quantum theory

Answer

To solve the question regarding the explanation of the photoelectric effect, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Photoelectric Effect**:
The photoelectric effect refers to the phenomenon where electrons are emitted from a material (usually a metal) when it is exposed to light of sufficient frequency.

2. **Identifying the Theories**:
We have four theories mentioned:
- Corpuscular Theory
- Wave Theory
- Electromagnetic Theory
- Quantum Theory

3. **Analyzing Each Theory**:
- **Corpuscular Theory**: This theory suggests that light consists of particles (corpuscles). While it does consider the particle nature of light, it does not adequately explain the photoelectric effect.
- **Wave Theory**: This theory describes light as a wave. However, it fails to explain why light below a certain frequency does not cause electron emission, regardless of its intensity.
- **Electromagnetic Theory**: This theory explains light as electromagnetic waves. Similar to the wave theory, it does not account for the threshold frequency necessary for the photoelectric effect.
- **Quantum Theory**: This theory, proposed by Albert Einstein, explains that light consists of packets of energy called photons. According to quantum theory, each photon has energy proportional to its frequency.

4. **Key Points of Quantum Theory Related to Photoelectric Effect**:
- The number of photoelectrons emitted is directly proportional to the intensity of the incident light.
- There exists a minimum frequency, known as the threshold frequency, below which no photoelectrons are emitted, regardless of the light's intensity. If the frequency is below this threshold, the photoelectric effect does not occur.

5. **Conclusion**:
Based on the analysis, the photoelectric effect can be explained on the basis of **Quantum Theory**. Therefore, the correct answer is option D: Quantum Theory.

### Final Answer:
The photoelectric effect can be explained on the basis of **Quantum Theory**.

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