Question

Why is mercury used in thermometers?

(a) It volume is proportional to square of increase of temperature

(b) It shows linear variation in volume with temperature

(c) Its volume remains constant with temperature

(d) Its volume decreases with increase in temperature

I have been asked this question in semester exam.

Origin of the question is Measurement of Temperature in division Thermal Properties of Matter of Physics – Class 11

Answer 1

Correct option is (b) It shows linear variation in volume with temperature

Explanation: For measuring temperature in a thermometer we need a substance whose physical properties change with temperature and can be easily related with temperature. Mercury’s volume increases linearly with increase in temperature and hence we can create a scale on the thermometer accordingly.