Question

Give two real-life applications of thermal expansion of solids.

Answer 1

Application of thermal expansions are:

1. Fitting the steel rim on a horse cartwheel.
2. Thermometers.

Fitting the steel rim on a horse cartwheel:

1. To fit the rim, it is first heated uniformly along its circumference till its diameter becomes slightly more than that of the wooden wheel.
2. The rim is then slipped over the wooden wheel before allowing to cool. On cooling, the rim contracts and makes a tight fit over the wooden wheel.

A thermometer is a device used to measure a given object's degree of hotness or coldness:

1. It consists of a glass tube inside which there is a liquid known as mercury. When the bulb of the thermometer is dipped in the given solution or object, the mercury starts to expand.
2. This expansion of mercury is read on the temperature. Depending on the reading, the temperature of the given object or solution can be determined.
3. Therefore, the working principle of the thermometer depends on the degree of hotness or coldness of the given solution or object.