Unit 2 Lesson 4

Which of these appliances is intended to convert electrical energy into sound energy?

• printer 
• refrigerator 
• electric heater 
• music amplifier

When Anu got home from school, she noticed that there was no electricity. Which of these items will she be able to use before the electricity comes back on?

• computer
• television
• violin
• toaster

The girl shown below is using an electrical appliance that has a motor.  Which energy transformation is she using?

• electrical energy into heat energy and energy of motion
• electrical energy into sound energy and chemical energy 
• sound energy into electrical energy and energy of motion
• energy of motion into electrical energy and sound energy 

The picture below shows a device made of a battery, a nail, and a long piece of copper wire. It converts electrical energy into a different form of energy.  Which term describes the device in the illustration?

• electric switch 
• electromagnet 
• electric motor
• electric generator 

Conservation of energy reduces the amount of electricity that needs to be generated. Which of these is a way to conserve electricity?

• Turn the television sound down so that it is not as loud. 
• Replace compact fluorescent light bulbs with incandescent light bulbs.
• Turn off the lights in a room when you leave it or when the lights are not needed. 
• Cool the house by leaving the refrigerator door open instead of using an air conditioner. 

Avrie starts to make an electric circuit using a battery, a light bulb, a paper clip, and some wire. She arranges the circuit’s parts as shown below.  Where would be the best place for Avrie to put a piece of wire in order to complete the circuit?

• between the top of the battery and the top of the paper clip
• between the top of the paper clip and the bottom of the battery
• between the top of the battery and the bottom of the light bulb
• between the top of the paper clip and the bottom of the light bulb 

What is the purpose of the wire in a circuit?

• to use the electric current
• to provide a source of electrical energy
• to connect the components
• to change the circuit from open to closed 

A student wanted to see how different materials affect the flow of electric current. He built a simple open circuit and used various objects to close the circuit. Then he recorded if the light bulb in the circuit glowed. The table below shows his results.  Which object blocks the flow of charges through a circuit?

• a nail
• a penny
• a wooden craft stick
• a pencil lead

What is the purpose of the the battery in a circuit?

• to use the electric current
• to provide a source of electrical energy 
• to connect the components
• to change the circuit from open to closed 

What is the purpose of the light bulb in a circuit?

• to use the electric current
• to provide a source of electrical energy
• to connect the components
• to change the circuit from open to closed