Heat Conduction

A rod is made of and wood and copper.
The rod is heated at the join the centre for about a minute.
At which point will lowest temperature , and at which point highest temperature?

• A

• B

• C

• D

A rod is made half of glass and half of copper. Four pins A. B. C and D are attached to the rod with wax. The rod is heated in the centre as shown.
The pins off when the wax is heated.
Which pin falls first?

• A

• B

• C

• D

Ice is by a metal gauze at the bottom of a tube containing water.
The water is heated strongly at the bp, but the ice only melts very slowly.

Why does the ice melt so slowly?

• Heat energy always travels upwards.

• Hot water is more dense than cold water.

• Metal gauze does not allow heat to pass through.

• Water is a poor conductor of heat.

One end of a copper rod is heated.
What is one method by which thermal energy is transferred in the copper rod?

• Free electrons transfer energy from the cooler end to the hotter end.

• Free electrons transfer energy from the hotter end to the cooler end.

• Molecules of copper move from the cooler end to the hotter end.

• Molecules of copper move from the hotter end to the cooler end.

......is a bad conductor of heat

• copper

• iron

• plastic

• Aluminium

What is the definition of CONDUCTION?

• When heat is transferred from objects like rays of light or electromagnetically.
• a  hot liquid or air that  expands, becomes less dense, and rises or becomes more dense, and sinks.
• When heat transfers from objects that are touching.
• When heat transfers through the heater or AC in your house.

What is heat conduction?

• The process of temperature transfer through a solid

• The process of heat transfer through radiation

• The process of heat transfer through a substance or material

• The process of slowing down heat transfer through a substance

What is meant by thermal equilibrium?

• The state when two objects are at the same temperature and no heat flows between them

• The state when two objects are at different temperatures and heat flows from the hotter object to the cooler object

• The state when two objects are at different temperatures and heat flows from the cooler object to the hotter object

• The state when two objects are at the same temperature and heat flows from the cooler object to the hotter object

Aluminium is an example of a good ​ (a)   , wood is an example of a good ​ (b)  

• conductor
• insulator
• metal
• organic material

Why is loft insulation so effective?

• It is an insulator and reduces noise

• It is an insulator and traps air which is also an insulator

• It is made of fibres that are flame retardant

• The reflective coating reflects heat back into a building.