Energy Unit Test

Why are some coffee cups composed of ceramic material?

Ceramic materials are insulators that limit heat transfer

An electric hotplate is used to cook food in an all-metal frying pan. Which best shows the path of the conduction of thermal energy?

Coil --> Pan --> Meat

A worker for an electrical company is preparing to fix a power line. Why would he put on rubber gloves before working with any power lines?

Rubber is a poor conductor of heat and electricity

What best explains why some cooking pans have rubber handles?

The rubber in the handles is a good insulator

What is an insulator?

a material through which current cannot move easily

Which of the following is the best conductor of heat?

a metal bowl

Which item is not a good conductor of electricity?

a rubber tire

Emily made a cup of tea and stirred it with a spoon. The spoon became warm. How was the heat from the tea transferred to the spoon?

conduction

A metal pan will heat up quickly when placed over a gas or electric burner. The metal pan is a good

conductor

Metals that easily transfer electricity are called

conductors

Which material is a good conductor of heat?

copper

Which material is the best conductor of heat at room temperature?

copper

Which material best conducts electricity?

copper pipe

Hot objects begin to cool as

energy in the object is transferred to the surrounding air

Which physical property is important to have in a material used in cookware?

good conductor of heat

Down feathers are used by many sleeping bag manufacturers because down feathers are

good insulators

What type of energy is transferred to a pot to make the water boil?

heat

The best example of heat transfer by convection is when

heat rises in a chimney.

Electrical wires are coated with a rubber or plastic because these materials are good

insulators

A conducting wire wrapped in plastic protects the user because the plastic

is a good electrical insulator

Plastic conducts very little thermal energy or electricity. Because of this property, plastic would most likely be used to cover

metal

Which material best conducts heat and electricity?

metal

Which is considered a good insulator of heat?

plastic, because heat is unable to flow easily through it

Sunlight passes through the windows of a car and causes the car seats to get hot. Which type of energy flow is involved in heating the seats?

radiation

Which would be the best conductor of electricity?

silver