RBSE Class 7 Science Notes Chapter 4 Heat

These comprehensive RBSE Class 7 Science Notes Chapter 4 Heat will give a brief overview of all the concepts.

RBSE Class 7 Science Chapter 4 Notes Heat

→ A reliable measure of the hotness of an object is its temperature.

→ Temperature is measured by a device called thermometer.

→ The thermometer that measures our body temperature is called a clinical thermometer.

→ A clinical thermometer reads temperature from 35°C to 42°C.

→ The normal temperature of human body is 37°C. The temperature should always be stated with its unit, °C. 

→ The range of a laboratory thermometer is generally from -10°C to 110°C.

→ The heat flows from a body at a higher temperature to a body at lower temperature. There are three ways by which heat can flow from one object to another. These are conduction, convection and radiation.

→ In solids, generally, the heat is transferred by conduction. In liquids and gases, the heat is transferred by convection. No medium is required for transfer of heat by radiation.

→ All hot bodies radiate heat. When this heat falls on some objects, a part of it is reflected, a part is absorbed and a part may be transmitted. The temperature of the object increases due to the absorbed part of the heat.

→ Wool is a poor conduction of heat. Moreover, there is air trapped in between the wool fibres. This air prevents the flow of heat from our body to cold surroundings. So, we feel warm.