Question

Early barometers used mercury to measure the pressure of the atmosphere. Nowadays, mercury is considered a health and safety risk, and so a different type of barometer is used.
What is the name given to this type of barometer?
A. Aneroid barometer
B. Simple barometer
C. Alcohol barometer
D. Vacuum barometer

Answer 1

Hint: We will not consider mercury-based thermometers here, along with any thermometer, which contains fluid. We will go through all the options and find which one serves the purpose.

Complete step by step answer:
Aneroid barometer: As a system which does not include liquid, an aneroid barometer is a pressure measurement tool. The aneroid barometer, invented in \[1844\] by French scientist Lucien vidi, uses a thin, lightweight metal box called an aneroid cell (capsule), constructed of beryllium and copper alloy. An effective spring stops the evacuated capsule (or normally multiple capsules, piled to sum up their movements) from collapsing. The cell is induced to expand or contract by slight changes in external air pressure.

Simple barometer: A simple barometer is made up of a long, mercury-filled glass tube (closed at one end, open at the other) and turned upside down into a mercury jar. The barometer operates much like a series of measurements by measuring the mercury in the glass tube against the outside air pressure.

Alcohol barometer: It is a barometer, which measures atmospheric pressure by measuring the movement of alcohol present in it.

Vacuum barometer: The use of vacuum pump oil as the working fluid in a barometer has contributed to the vacuum barometer being developed. Vacuum pump oil does have low vapour pressure and is available in a number of densities; to increase the oil column height, the lowest density vacuum oil was selected for the PSU barometer.

From the above descriptions it can be seen that aneroid barometer is the leading contender among the following. It is now widely used as it doesn’t contain any fluid.

So, the correct answer is “Option A”.

Note:
This question can be answered if you know which thermometer doesn’t contain any fluid in it. In one of the given choices, there is a vacuum barometer, which may be understood as containing vacuum, but the thing is not like that. Rather it contains vacuum pump oil.