Practial unit of pressure in S. I system is

Options

A. torr
B. Bar
C. atmosphere
D. Pascal

Answer

To determine the practical unit of pressure in the SI system, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Units of Pressure**:
- The common units of pressure include Pascal (Pa), Atmosphere (atm), Bar, and Torr.

2. **Understand the SI Unit of Pressure**:
- The SI unit of pressure is defined as one Newton per square meter, which is known as Pascal (Pa).

3. **Compare the Units**:
- 1 atm = 101325 Pa
- 1 bar = 100000 Pa (approximately equal to 1 atm)
- 1 Torr = 760 mmHg = 101325 Pa / 760 ≈ 133.322 Pa

4. **Evaluate Practical Usage**:
- While atm and bar are larger units, they are not as practical for scientific calculations where smaller values of pressure need to be measured. Using Pascal allows for easier calculations without dealing with large numbers or many decimal points.

5. **Conclusion**:
- Since Pascal is the standard unit in the SI system and is practical for both small and large values of pressure, the answer to the question is **Pascal (Pa)**.

### Final Answer:
The practical unit of pressure in the SI system is **Pascal (Pa)**.

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