Question

State one application of thermal expansion of liquids.

Answer 1

Hint: The liquid expands as it is heated. The heat from the hands increases the kinetic energy of molecules of liquid, so they move faster on average and tend to move further apart as they collide and bump. This results in expansion of liquid.

Complete answer:
Mercury is a metal found in a liquid state. It expands more and uniformly over a wide range of temperature. So the mercury is used as a thermometric liquid. Thermal expansion of bimetallic strips used as a heat operated switch in circuits of automatic equipment like iron box, fire alarm, electric heater, etc. Some thermometer work on the principle of expansion of liquids in automobile engines useful work is done by expansion of gases. Mercury’s volume coefficient of expansion is $0.00018$, so it expands by $0.018\% $ in volume for every degree of temperature increase.

Note:
In physics, thermal expansion is the likelihood of matter to change in volume in response to a change in temperature. When a substance is heated, its basic particles move around more quickly and by doing so generally maintains a greater average separation. Thermal expansion occurs when an object expands or gets larger due to an increase in temperature. Thermal expansion occurs because heated molecules move faster and take up more space.