2 DOS Week 5

Objects that conduct electricity can easily carry an electrical charge. Which of the following materials best conducts electricity? 

• cotton string
• copper wire
• rubber sheets
• plastic tubing

Which of the following objects is the best insulator of electricity?

• chair
• apple
• paperclip
• water

Which part of the pencil is most likely to be the poorest insulator of electricity?

• w
• x
• y
• z

Which of the following describes an example of static electricity? 

• motor spins continuously because of electricity and magnetism.
• A radio plays music loudly even though it is not plugged into an outlet. 
• When a switch is flipped, a light immediately turns on.
• A plastic comb attracts small pieces of paper after it is rubbed with another object

Which of the following describes an example of current electricity?

• A lightning bolt produces sound and light. 
•  A student feels a shock when she touches a doorknob after walking across a carpeted surface
•  A balloon sticks to the wall after being rubbed with a piece of wool
• A battery connected to a motor in a toy car allows the car to move.

Eva constructed the device shown to test whether certain objects can conduct electricity.
Eva touched a particular object to both metal terminals at the same time. The light bulb did not light up. What is most likely true about the object?

• It produced electricity.
• It was a conductor.
• It was an insulator.
• It had static electricity.

The picture shows a simple electric circuit.
What carries electric energy in the circuit? 

• the fan 
• the battery
•  the wires
• the light bulb

Which of the following materials is a good conductor of electricity? 

• wood
• cloth
• silver
• air

Marcus has a circuit that uses a battery to light up a light bulb. He changes the circuit to have a paper clip attached to the wires as shown in the picture.
What should Marcus predict will happen when he connects the second wire to the paper clip? 

• The battery will die.
• The light bulb will break
• The paper clip will turn black.
• The light bulb will light up. 

Which of these is a chemical change?

• a pulley lifts a load
• Silver tarnishes
• a rubber band stretches