Conduction - Oxford AQA IGCSE Physics

What is thermal conduction?

• The process of energy transfer by vibrating particles in a substance. It is the main method of thermal energy transfer in solids.

• The movement of heat through fluids by the motion of the fluid itself.

• The transfer of heat through direct contact between materials.

• The process of energy transfer through electromagnetic waves.

Why are metals good thermal conductors?

• They have a low density which allows heat to pass through easily.

• They have a high number of free electrons that gain energy and transfer it quickly through the metal.

• They are solid at room temperature, which helps in heat conduction.

• They have a crystalline structure that enhances thermal conductivity.

How do insulated mugs work?

• They have a vacuum between two layers to reduce energy transfer by conduction, maintaining the drink's temperature longer.

• They are made of metal that conducts heat quickly, keeping drinks warm.

• They are filled with foam to trap heat inside.

• They have a double wall filled with water to maintain temperature.

How do free electrons contribute to conduction in metals?

• Free electrons gain energy and travel through the metal, speeding up thermal conduction by colliding with other electrons and metal ions.

• Free electrons are trapped in the metal and do not contribute to conduction.

• Free electrons only move at low temperatures, which slows down conduction.

• Free electrons create a barrier that prevents conduction in metals.

In which direction does energy transfer occur during conduction?

• From cold to hot

• From hot to cold

• In a circular motion

• In random directions

What is thermal equilibrium?

• Thermal equilibrium is achieved when energy is evenly distributed throughout the substance.

• Thermal equilibrium occurs when a substance is at its boiling point.

• Thermal equilibrium is the state when a substance is completely frozen.

• Thermal equilibrium is when a substance is in a state of constant motion.

What is an insulator?

• A substance that is a good thermal conductor.

• A substance that is a poor thermal conductor, used to reduce energy transfers.

• A material that enhances energy transfer.

• A device that generates heat.

What happens when two objects of different temperatures come in contact?

• Thermal energy is transferred from the cooler object to the hotter object.

• Thermal energy is transferred from the hotter object to the cooler object.

• No energy transfer occurs between the objects.

• Both objects reach the same temperature instantly.

What occurs when a substance is heated in terms of particle movement?

• The particles start to move around (vibrate) more, transferring energy from their kinetic store to the kinetic store of neighboring particles as they collide.

• The particles become stationary and do not move at all.

• The particles move slower and lose energy to their surroundings.

• The particles expand and create a vacuum around them.

Give examples of good insulators.

• wool

• metal

• glass

• concrete