Question

What is a thermometer and how does it work. [3 MARKS]

Answer 1

Thermometer definition : 1 Mark
Working : 2 Marks

A thermometer is an instrument which is used to measure the temperature of a substance. It is a measure of how excited the molecules of a substance are.

When the bulb, which is a good conductor of heat, of a thermometer comes in contact with an object, the bulb (usually at a lower temperature) recieves heat from the object. This heat is conducted to the liquid inside the thermometer. This liquid which is usually Mercury, expands uniformly depending on the amount of heat absorbed by the bulb. Depending on how much the liquid has expanded, the thermometer gives the respective reading.