The product of the time period of a wave and its frequency is

Options

A. infinite
B. zero
C. more than unity but less than infinity
D. unity

Explanation

To solve the question regarding the product of the time period of a wave and its frequency, we can follow these steps:

### Step-by-Step Solution:

1. **Define Time Period and Frequency**:
- The time period (T) of a wave is the time taken for one complete cycle of the wave.
- Frequency (f) is the number of cycles that occur in one second.

2. **Understand the Relationship**:
- There is a fundamental relationship between the time period and frequency of a wave given by the formula:
\[ T = \frac{1}{f} \]
- This means that the time period is inversely proportional to the frequency.

3. **Calculate the Product**:
- We need to find the product of the time period (T) and frequency (f):
\[ T \times f \]
- Substituting the relationship from step 2 into this equation gives:
\[ T \times f = \left(\frac{1}{f}\right) \times f \]

4. **Simplify the Expression**:
- When we simplify the expression:
\[ T \times f = 1 \]

5. **Conclusion**:
- Therefore, the product of the time period of a wave and its frequency is always equal to 1.

### Final Answer:
The product of the time period of a wave and its frequency is **1**.

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