If the distance between a crest and its consecutive trough is L, then the wavelength is given by

Options

A. L/2
B. L
C. 4L
D. 2L

Answer

To find the wavelength given that the distance between a crest and its consecutive trough is L, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- A **crest** is the highest point of a wave, while a **trough** is the lowest point. The distance between them is what we need to analyze.

2. **Visualizing the Wave**:
- Draw a simple wave diagram. Mark the crest (C) and the trough (T). The distance from the crest to the trough is L.

3. **Identifying the Distance**:
- The distance from a crest to the next trough (C to T) is half of the wavelength (λ/2). This is because a full wavelength (λ) consists of one crest and one trough.

4. **Setting Up the Equation**:
- Since the distance from the crest to the trough is given as L, we can write the equation:
\[ L = \frac{\lambda}{2} \]

5. **Solving for Wavelength**:
- To find the wavelength (λ), we can rearrange the equation:
\[ \lambda = 2L \]

6. **Conclusion**:
- Thus, the wavelength is given by:
\[ \lambda = 2L \]

### Final Answer:
The wavelength (λ) is equal to \( 2L \).

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