Question

Give two examples of appliances that make use of convection currents.

Answer 1

Answer:

Convection refers to the process of transfer of heat or energy through a fluid (gas or liquid) from high temperature to low temperature. Convection is one of the three types of heat transfer; the other two being radiation and conduction. Conduction refers to the transfer of heat between bodies which are in physical contact; whereas, in radiation, energy is emitted in the form of electromagnetic waves.

ex-

1) Blood Circulation in Warm-Blooded Mammals

2)boiling water

3)breeze

Explanation:

Answer 2

Answer:

Convection is the transfer of heat by the movement of particles. Convection is the primary mode of heat transfer in fluids (liquid and gases).

A few applications of convection are given below:

1. Boiling water - One of the most common examples of convection is boiling water.Hot air rises up (hot air is light so it rises up), the cooler air from the sides rush in to take it's place, get's heated up and rise upwards. Again the cold air from the sides takes it's place and then rises up. This continues until the entire water is heated.
2. Land breeze and sea breeze - Convection currents give rise to land breeze and sea breeze in coastal regions..
3. Exhaust fans in kitchens are always fitted high, close to the ceiling so that they can remove the hot air that rises up.
4. Room heaters are placed on the floor of a room. When the cool air is heated, it rises up and the cold air flows down to the floor. This results in effective heating of the entire room.

Convection currents:

• Gasses expand on heating thus convection currents are easily set up due to the difference of densities of air at various parts in the atmosphere.
• The upward and downward movement of molecules of water or air is called a convection current. convection currents occur on a large scale in nature.
• The day-to-day temperature changes in the atmosphere result from the circulation of warm or cold air that travels across the regions, land and sea breezes.