SSC CGL 2022 PYQ — Question 34

The correct answer is Option 3 i.e. Invention of the mercury barometer

Evangelista Torricelli, an Italian physicist, and mathematician who was born in Faenza, Romagna, on October 15, 1608, and died in Florence on October 25, 1647, is credited with developing the barometer and contributing to the creation of integral calculus. The first man to create a sustained vacuum and to discover the principle of a barometer.

Experiment by Torricelli-

Torricelli wrote about an experiment in 1646 that involved filling a glass tube about a meter long with mercury, sealing one end, and then inverting it into a dish of mercury. Some mercury, but not all of it, leaked into the dish from the glass tube. To explain this, Torricelli assumed that mercury will drain from the glass tube until the forces exerted by the mercury column and the environment on the liquid's surface outside the tube are precisely balanced. According to Torricelli, the mercury column's height would fluctuate from day to day as a result of variations in atmospheric pressure. Today, his apparatus is known as a barometer, from the Greek baros, meaning "weight," because it measures the weight of the atmosphere.