Unit 11-12 Test Review

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

• resistance

• voltage difference

• current

• static electricity

Electric charges always flow from ______ areas to ______ areas.

• positive ; negative

• positive ; neutral

• negative ; positive

• neutral ; negative

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

• insulator

• conductor

• fuse

• circuit breaker

Which of the following statements about electric charge is true?

• objects must be touching one 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

Which of the following could be used as an insulator?

• plastic plate

• silver spoon

• copper wire

• gold necklace

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

• thicker wire

• shorter wire

• increase the temperature of the wire

• using silver instead of copper for the wire

What is the current produced by a 120 V battery flowing through a resistance of 6 ohms?

• 0.05 amps

• 20 amps

• 114 amps

• 720 amps

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

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

• increasing the current flowing 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

Silver has a resistance of 0.0198 ohms. What voltage would produce a current of 20 amps?

• 0.00099 V

• 0.4 V

• 20.0198 V

• 1010 V