MCQ Detailed View

Pressure is defined as the force exerted per unit area. It is one of the key concepts in Physics and is widely used in various scientific and engineering fields such as fluid mechanics, thermodynamics, meteorology, and material science. The standard SI unit of pressure is the Pascal (Pa), which is equal to one newton per square meter (N/m²).

However, pressure can also be measured in several other units depending on the field of application. For example, in meteorology and atmospheric studies, pressure is often expressed in bar. One bar is equal to $100,000\text{Pa}$, which is very close to the standard atmospheric pressure at sea level.

In vacuum physics and studies involving gases, pressure is frequently measured in torr. One torr is defined as 1760\frac{1}{760}7601 of an atmosphere, approximately equal to 133.3 Pa. The torr is named after Evangelista Torricelli, who invented the mercury barometer and made important contributions to fluid and gas studies.

Thus, while Pascal (Pa) is the official SI unit, both bar and torr are also recognized as valid units of pressure in specialized fields. That is why the correct answer to this question is “All of these.”

Understanding pressure units is essential because they help us interpret everyday phenomena, such as why air pressure decreases with altitude, how blood pressure is measured, and how gases behave under different conditions. It also plays a key role in engineering, where pressure is crucial in designing hydraulic machines, pipelines, and industrial systems.