Unit 8 Review

First and Last Name

1. The force or push that causes electric charges to move is called

• resistance
• voltage difference
• current
• static electricity

2. Electric charges always flow from____ areas to______ areas.

• positive, negative
• negative, positive
• positive, neutral
• neutral, negative

3. A material through which electrons do NOT flow easily is a(n)______.

• insulator
• fuse
• conductor
• circuit breaker

4. Which of the following statements about electric charge is true?

• Objects must be touching on another to exert electrical force.
• Electrical forces act at a distance.
• Air cannot conduct electricity; it is conducted only by solid materials.
• Opposite electric charges always repel one another.

5. Mr. Robinson and his class are conducting an experiment. The class needs to choose a good insulator. Which of the following could be used as an insulator?

• plastic plate
• silver spoon
• copper wire
• gold necklace

6. Which of the following will increase the resistance of a wire?

• using a thicker/wider wire
• using a shorter wire
• increasing the temperature of the wire
• using silver instead of copper

7. What is the current produced by a 9-volt battery flowing through a resistance of 0.2 ohms?

• 1.8 amps
• 45 amps
• 0.022 amps
• 8.8 amps

8. Which two areas of physical science are closely related to the development of electric motors and generators?

• sound and light
• electricity and sound
• light and magnetism
• electricity and magnetism

9. Which of the following will decrease the strength of the magnetic field around a wire?

• increasing the current flow through the wire
• using less loops around the iron core
• flipping the direction of the current flowing through the wire
• using a larger iron core