Q1: Barometres are used to measure

ANS:C - atmospheric pressure

Barometers are used to measure atmospheric pressure. A barometer is an instrument used to measure atmospheric pressure, which is the force exerted by the weight of the atmosphere above a certain point on Earth's surface. Atmospheric pressure is an important parameter in weather forecasting, as it affects weather patterns and conditions. Barometers come in various types, including mercury barometers, aneroid barometers, and electronic barometers. They work by measuring the height of a column of mercury (or using other methods) in a sealed tube, which changes with variations in atmospheric pressure. Therefore, barometers are primarily used to measure atmospheric pressure.