Heat Transfer in Nature — Science STD 7 — Question

1. Conduction
→ Conduction is the transfer of heat through a material without any movement of the material itself. It mainly occurs in solids.
→ Heat is transferred from the hotter part to the colder part due to the collision of particles.
Example:
→ When you heat one end of a metal rod, the other end also gets hot after some time. The heat is transferred through the metal by conduction.
 → A metal pan on a stove gets hot because the heat from the stove is conducted through the metal base of the pan.
2. Convection
→ Convection is the transfer of heat by the movement of a fluid (liquid or gas).
→ When a fluid is heated, it becomes less dense and rises, while the cooler, denser fluid sinks. This creates a current that transfers heat.
Example:
Boiling Water: When you boil water in a kettle, the water at the bottom gets heated, becomes lighter, and rises. The cooler water from the top sinks to take its place, creating a convection current.
3. Radiation
→ Radiation is the transfer of heat through electromagnetic waves.
→ Unlike conduction and convection, radiation does not require a medium to transfer heat.
Example:
Sun's Heat: The heat from the sun reaches the Earth through radiation.
Room Heater: When you sit near a room heater, you feel warm because the heater radiates heat directly to you.