ICSE Physics Class 7 Notes Chapter 5 Heat
→ Heat is a form of energy that leads to the sensations of hotness or coldness.
→ Temperature is the degree of hotness and coldness of a body.
→ Thermometer is used to measure temperature.
→ The S.I. unit of temperature is °C.
→ The most common liquid for a thermometer is mercury.
→ The main sources of heat are (0 Fire (ii) Sun (iii) Electricity.
→ Those substances which can easily catch fire are called inflammable substances.
→ Those substances which are fire resistant are called non-inflammable substances.
→ The fixed temperature at which freezing of liquid occurs is known as freezing point.
→ The temperature at which vapourisation occurs is known as the boiling point.
→ Substances through which heat is easily conducted are called good conductors e.g. silver, gold, copper etc.
→ Substances through which heat is not easily conducted are called Insultors.
→ Radiation is the process of transfer of heat from a hot body to a cold body without affecting the intermediate medium