The Standard Atmosphere: Definition and Pressure

The standard atmosphere is a unit of pressure commonly used in meteorology, aviation, and other scientific fields. It is defined as 101325 Pascal, which is equivalent to 1013.25 hPa (hectopascals) or 14.7 pounds per square inch (psi).

Explanation:

The standard atmosphere is a reference pressure used to compare and calculate atmospheric conditions. It provides a common baseline for measuring and comparing pressure in different locations and altitudes. The pressure at sea level is typically defined as the standard atmosphere, and it gradually decreases with increasing altitude.

The pressure unit used in the standard atmosphere is Pascal, which is the SI unit of pressure. Pascal is defined as one newton per square meter, where a newton is the force required to accelerate a one-kilogram mass by one meter per second squared. This unit allows for precise and consistent measurements of pressure.

Other Options Explained:

Let's now discuss the other options given in the question and why they are not the correct answers:

b) 1325 Pascal: This option is not the correct answer because it is significantly lower than the defined value of the standard atmosphere. It does not match the commonly accepted reference pressure.

c) 10132 Pascal: This option is also incorrect because it is higher than the defined value of the standard atmosphere. It does not align with the widely accepted standard pressure at sea level.

d) 11325 Pascal: This option is incorrect because it is higher than the defined value of the standard atmosphere. It does not match the commonly used reference pressure.

Conclusion:

In conclusion, the correct answer is option 'A', which states that the standard atmosphere is defined as 101325 Pascal. This unit of pressure provides a reference point for comparing and calculating atmospheric conditions and is widely used in meteorology, aviation, and other scientific fields.