Question

Mention one application of expansion on heating and contraction on cooling

Answer 1

expansion - to fit metal rim on a wooden wheel which is smaller than the wheel by heating rim.
contraction- we pour cold water over the metal rim, so it contracts and fits tightly on the wheel.

Answer 2

Answer:

• The working of a liquid thermometer is an application of expansion on heating and contraction on cooling.
• Thermometers filled with a liquid like mercury works by the expansion of the liquid when in contact with a hot body or object and contraction when removed from the hot body or object.
• While checking the temperature, the bulb of the thermometer filled with mercury comes in contact with the hot body which causes expansion of the liquid and rises in level and goes up the thermometer scale indicating a temperature rise.
• Upon removal from the hot body, the mercury cools down and contract to the original level in the bulb.