IGCSE - Thermal Expansion

 

A wooden wheel can be strengthened by putting a tight circle of iron around it. 

Which action would make it easier to fit the circle over the wood? 

• cooling the iron circle 

• heating the iron circle 

• heating the wooden wheel and cooling the iron circle 

• heating the wooden wheel but not heating or cooling the iron circle 

Which one shows the relative order of thermal expansion of solids, liquids and gases?

• solid > liquids > gases

• solid > gases > liquids

• gases > solids > liquids

• gases > liquids > solids

The diagram shows electricity cables being put up on a warm day. The cables are left loose

between the poles, as shown in the diagram.

Why are the cables left loose?

• They will expand on very warm days.

• They will expand on cold days.

• They will contract on very warm days.

• They will contract on cold days.

A glass bottle has a metal cap. The cap fits very tightly and is difficult to remove.

The cap and the neck of the bottle are dipped in a bowl of hot water. The cap can be removed more easily.

What happens to allow the cap to be removed more easily from the bottle?

• The cap contracts.

• The glass bottle contracts.

• The cap expands.

• The glass bottle expands

The diagram shows the shape of the bimetallic strip before and after heating.

Which statement is correct?

• Metal P expands more than metal Q on heating.

• Metal P contracts more than metal Q on heating.

• Metal Q expands more than metal P on heating.

• Metal Q contracts more than metal P on heating.

When a bridge is built, a gap is left between each concrete slab.

Why are these gaps left?

• The gaps contract on cold days.

• The gaps expand on warm days.

• Concrete contracts on warm days.

• Concrete expands on warm days.

In terms of molecules, explain why solids expand when they are heated

X and Y are strips of two different metals, joined together along their length. Together they are called a bimetallic strip. X expands more than Y for the same temperature rise.

The temperature rises and the bimetallic strip bends.

State what happens to the current in the circuit,