Electricity and Magnetism Test CP

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.

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

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

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

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

• A. sound and light

• B. electricity and sound

• C. light and magnetism

• D. 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 100 amps?

• 1.98 V

• 0.000198 V

• 5,050 V

• 100.0198 V

This contains a piece of metal that melts if it gets too hot in order to open a circuit.

• conductor

• insulator

• fuse

• circuit breaker

What does the symbol labeled #1 represent?

• light

• battery

• resistor

• switch

What does the symbol labeled #2 represent?

• light

• battery

• resistor

• switch