Huygens wave theory allows us to know

Options

A. The wavelength of the wave
B. The velocity of the wave
C. The amplitude of the wave
D. The propagation of wave fronts

Answer

**Step-by-Step Solution:**

1. **Understanding Huygens' Wave Theory**: Huygens' wave theory is a fundamental principle in wave optics that describes how waves propagate. It states that every point on a wave front can be considered as a source of secondary wavelets.

2. **Primary Wave Front**: When a point source (S) emits waves, it creates a spherical wave front. This initial wave front is referred to as the primary wave front.

3. **Secondary Wavelets**: According to Huygens' principle, each point on the primary wave front acts as a new source of disturbance, generating secondary wavelets. These wavelets spread out in all directions from each point on the primary wave front.

4. **Formation of Secondary Wave Front**: The surface formed by the collection of these secondary wavelets, as they propagate forward, creates a new wave front known as the secondary wave front.

5. **Propagation of Wave Fronts**: This process continues, where each new wave front acts as a primary wave front for the generation of further secondary wavelets, leading to the continuous propagation of waves.

6. **Conclusion**: Huygens' wave theory allows us to understand the propagation of wave fronts through the concept of secondary wavelets originating from every point on the wave front.

**Final Answer**: Huygens' wave theory allows us to know how wave fronts propagate through the generation of secondary wavelets from every point on the primary wave front.

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