Q1: Differential manometers are used to measure

ANS:B - difference in pressure at two points

Differential manometers are primarily used to measure the difference in pressure at two points in a fluid system. They are commonly employed in various engineering and scientific applications to monitor pressure differences across components such as pipes, channels, vessels, and equipment. This allows engineers and technicians to assess the performance, efficiency, and safety of fluid systems. Differential manometers work by comparing the pressure at one point in the system to the pressure at another point, typically using a column of liquid (such as mercury, water, or oil) within a transparent tube. The difference in liquid levels in the two arms of the manometer provides a direct indication of the pressure difference between the two points being measured. While differential manometers can be used to measure pressure differences in various contexts, they are not typically used to measure atmospheric pressure or very low pressure. For atmospheric pressure measurements, barometers or absolute pressure gauges are more commonly used. Similarly, for very low pressure measurements, specialized instruments such as vacuum gauges or ultra-sensitive pressure transducers are employed.