Effects of Heat Application

Which of the following is not true of the Particle Model of Matter?

• All substances are made up of tiny particles

• The particles have no space between them

• The particles are always in motion

• The particles have space between them

What can be done to ensure that the tracks do not become crooked like this? You may choose more than one answer.

• Expansion gap should be included between adjacent tracks.

• Rollers should be placed below the train tracks.

• A longer track should be used.

• Expansion bends should be included in the train track design

A bimetallic strip is made up of _____________________ welded together.

• two metals of the same kind 
• two different metals that expand and contract unequally
• two different metals that expand and contract equally

The diagrams show a bimetallic strip when it is at room temperature and after it has been cooled.

The change in shape occurs because

• Invar and brass contract by equal amounts

• Brass expands when it cools down

• Brass contracts more than invar

• Invar contracts more than brass

What can we say about metal A and metal B from the diagram?

• Metal A is a good conductor of heat.

• Metal A contracts more than Metal B.

• Metal B contracts more than Metal A.

• Metal A expands more than Metal B.

The picture shows a bimetallic strip in a fire alarm. When there is a fire outbreak, the bimetallic strip will get hot and....

• becomes shorter, completes the circuit and the electric bell rings

• becomes longer, break the circuit and the electric bell does not ring

• bend upwards, break the circuit and the electric bell sounds

• bend downwards, completes the circuit and the electric bell sounds

when heating the bimetallic coil , it .......

• uncurl

• curl

• drop down

Bimetallic strips are commonly found in all of the following except...

• electric iron.

• rice cooker.

• refrigerator.

• clinical thermometer.

What is a thermostat?

• It is a heating device

• It is a device that keeps temperature high all the time.

• It is a device that keeps temperature low all the time.

• It is a device that keeps temperature constant all the time.