Convection

Question 1

Convection of heat…

Answer 1

Liquids and gases only

Question 2

When does convection occur

Answer 2

Convection occurs when the more energetic particles move form the hotter reign to the cooler region and take their heat energy with them

Question 3

The immersion heater example Step 1

Answer 3

• Heat energy is transferred from the heater coils to the water by conduction

Question 4

The immersion heater example Step 2

Answer 4

The particles near the coils get more energy, so they start moving around faster

Question 5

The immersion heater example Step 3

Answer 5

This means there is more distance between them i.e. the water expands and becomes less dense

Question 6

The immersion heater example Step 4

Answer 6

This reduction in density means that the hotter water tends to rise above the denser, cooler water

Question 7

The immersion heater example Step 5

Answer 7

As the water rises it displaces (moves) the colder water out of the way, making it sink towards the heater coils.

Question 8

The immersion heater example Step 6

Answer 8

The cold water is then heated by the coils and rises. You end up with convection currents going up, round and down, circulating the heat energy through the water

Question 9

Convection currents are about

Answer 9

Changes in density

Question 10

The radiator example

Answer 10

Hot, less dense air by the radiator rise and denser, cooler air flows to replace it