Question

List out the uses of the barometer.

Answer 1

Pressure

1. Pressure is defined as the force per unit area.
2. The unit of pressure is pascal or $Pa$.
3. Atmospheric pressure is the amount of pressure exerted by the atmosphere on the surface of the earth.
4. Atmospheric pressure is measured by adding mercury to a container and placing a vacuum inverted glass tube on top of it.
5. Due to the pressure exerted on the fluid mercury outside the glass tube by the atmosphere, the mercury column inside the glass tube will increase or decrease according to the magnitude of pressure applied.
6. The level of the mercury column is measured by the scale present in the glass tube, which gives the measure of the pressure at that point.
7. At ground level, this mercury column is at a height $760mm$, which is termed one atmospheric pressure.
8. Hence, $1atm=760mmofHg$.

Barometer

1. A barometer is an instrument that is used to measure the atmospheric pressure at that point.
2. Hence, using this measure for pressure a barometer can be used for weather forecasting.
3. It can also be used to check if the pressure inside an aircraft is balanced.
4. Since the pressure inside a fluid is equal throughout, a barometer can be used to measure the pressure of the entire fluid.