Heat Transfer and Household Appliances

Name the method of heat transfers used to cook the food in the picture displayed?

• radiation

• conduction

• convection

• evaporation

Where is the heating element located in a regular oven?

• at the side

• at the bottom

• at the top

• at the back

In which direction does hot air flow in an oven?

• bottom to top

• top to bottom

• circular motion

• side to side

In what direction does cold air moves inside an oven?

• bottom to top

• top to bottom

• circular motion

• side to side

The material used to make the heating element of cooking appliances is :

• a conductor

• an insulator

What type of material is mineral wool?

• a conductor

• an insulator

• a metal

• a semi-conductor

What is the purpose of mineral wool between the inner and outer walls of an oven ?

• add to the over all stability of the appliance

• reduces heat loss by convection

• prevents food burning

• 1 & 2

Define the term insulator?

• any material or substance that conducts heat

• any material or substance that does not conducts heat

• any material or substance that is on the inside of another

• any material or substance that is on the outside of another

What is the purpose of the insulation material between the inner wall and outer casing of a refrigerator?

• trap heat inside the refrigerator

• prevent heat transfer from the casing of the refrigerator to the inside

• add to the overall stability of the appliance

• prevent electrical fires

In what direction does warm air move in a refrigerator?

• below the freezer, upwards

• from the freezer , downwards

• circular motion

• front to back