Which of the following prediction of corpuscular theory was proved wrong by Huygens' wave model ?

Options

A. Frequncy of the wave remains same during refraction
B. speed of the light increases in denser medium
C. Angle of of incidence is equal to angle of reflection
D. All of these

Answer

To solve the question, "Which of the following predictions of corpuscular theory was proved wrong by Huygens' wave model?", we need to analyze the options provided and understand the implications of Huygens' wave theory compared to corpuscular theory.

### Step-by-Step Solution:

1. **Understanding Corpuscular Theory**:
- The corpuscular theory, proposed by Isaac Newton, posited that light is made up of particles (corpuscles). According to this theory, light travels in straight lines and has certain properties like speed and direction.

2. **Understanding Huygens' Wave Model**:
- Huygens' wave theory, on the other hand, describes light as a wave. It introduces the concept of wavefronts and states that every point on a wavefront can be considered a source of secondary wavelets. This model accounts for phenomena such as diffraction and interference, which corpuscular theory could not explain.

3. **Analyzing the Options**:
- **Option 1**: "Frequency of the wave remains the same during refraction."
- According to Huygens' theory, when light passes from one medium to another, its frequency remains constant, while its speed and wavelength change. This is consistent with the wave model and does not contradict corpuscular theory.
- **Option 2**: "Speed of light increases in denser medium."
- This statement is incorrect according to Huygens' wave model. When light enters a denser medium, its speed decreases. This contradicts the corpuscular theory, which does not account for the change in speed due to medium density.
- **Option 3**: "Angle of incidence is equal to the angle of reflection."
- This is a fundamental law of reflection that is valid in both theories. It does not contradict either model.
- **Option 4**: "All of these."
- This option suggests that all previous statements are incorrect, which is not the case.

4. **Conclusion**:
- The prediction of the corpuscular theory that was proved wrong by Huygens' wave model is **Option 2**: "Speed of light increases in denser medium."

### Final Answer:
The prediction of corpuscular theory that was proved wrong by Huygens' wave model is: **Speed of light increases in denser medium.**