SI unit of time period is :

Options

A. second
B. minute
C. hour
D. nanosecond

Explanation

To find the SI unit of time period, we can follow these steps:

### Step-by-Step Solution:

1. **Define Time Period**: The time period is defined as the time taken to complete one full cycle of oscillation or wave. It is a measure of how long it takes for a repeating event to occur.

2. **Identify the SI Unit of Time**: The SI unit of time is the second. This is a standard unit used in the International System of Units (SI).

3. **Notation**: The second is denoted by the symbol 's'.

4. **Comparison with Other Units**: While the second is the SI unit, it's important to note that there are other units of time such as minutes and hours. For example:
- 1 minute = 60 seconds
- 1 hour = 60 minutes = 3600 seconds
- 1 nanosecond = \(10^{-9}\) seconds

5. **Conclusion**: Therefore, the SI unit of time period is the second (s).

### Final Answer:
The SI unit of time period is the second (s).

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