Question

The vacuum above the surface of the mercury in a barometer is called
(A) Newton’s vacuum
(B) Torricelli’s vacuum
(C) Einstein’s vacuum
(D) Rutherford’s vacuum

Answer 1

Hint: All the options given to us are names of famous scientists, so if we can find which scientist is related to the study of barometers or had some contribution to the mercury barometer, we will have our answer. To proceed with that, we need to first know about the mercury barometer.

Complete step by step answer:
In the simplest barometer, the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column. The height of the mercury column varies with atmospheric pressure and can be used to calculate the atmospheric pressure.
When the tube filled with mercury is upended into the cistern, there is a fall in the mercury level which leads to the creation of a vacuum space near the top of the tube. This vacuum contains mercury vapours. Evangelista Torricelli was the first scientist to explain the rise and fall of the mercury column and he also made the design of the first mercury barometer hence this vacuum is named after him as Torricelli’s vacuum.
Mercury barometer has various applications in fluid mechanics, can be used to determine the height of a place and hence can be used as an altimeter in aircraft. Weather forecasting and analysis also make use of mercury barometers.
The correct answer is (B) Torricelli’s vacuum

Note: We saw the important contribution of Evangelist Torricelli. All the other scientists mentioned in the options are known for their most important works. Isaac Newton is best known for his theory about the laws of gravity and his three laws of motion. Albert Einstein is best known for his theory of relativity which establishes the relationship between mass and energy. Rutherford is best known for his gold foil experiment to determine the model of an atom.