Question

which is the si unit for pressure?

pa
torr
psi
inhg

Explanation:

Identify the definition of pressure and its SI unit

$$ \text{Pressure } (P) = \frac{\text{Force } (F)}{\text{Area } (A)} $$

The SI unit for force is the Newton (\(\text{N}\)) and for area is the square meter (\(\text{m}^2\)). Therefore, the SI derived unit for pressure is:

$$ 1\text{ N/m}^2 = 1\text{ Pascal } (\text{Pa}) $$

Evaluate the given options

• \(\text{Pa}\) (Pascal): The official SI derived unit for pressure.
• \(\text{Torr}\): A non-SI unit of pressure based on an absolute scale (equal to \(1/760\) of a standard atmosphere).
• \(\text{psi}\) (pounds per square inch): An imperial/US customary unit of pressure.
• \(\text{inHg}\) (inches of mercury): A non-SI unit of pressure commonly used in meteorology.

Answer:

• (A) Pa (Correct answer)
• (B) Torr
• (C) psi
• (D) inHg