Which of the following describes the working principle of a simple mercury barometer?

💡 Solution & Explanation

A simple mercury barometer operates by balancing the downward gravitational force exerted by the weight of a vertical column of liquid mercury against the upward force of atmospheric pressure acting on the mercury reservoir below. It relies on hydrostatic equilibrium rather than fluid motion principles like Bernoulli's theorem or buoyancy concepts like Archimedes' principle. Evangelista Torricelli invented this device in the seventeenth century. Barometric readings are fundamental for daily meteorological forecasting.