Unit 3
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Unit Test A
Electricity and Magnetism
Key Concepts
Choose the letter of the best answer.
1. Which of the following is a ferromagnetic material?
A. aluminum
B. copper
C. diamond
D. iron
2. The following instrument measures, detects, and determines the direction of a small electric current:
What is the name of this instrument?
A. amplifier
B. inductor
C. galvanometer
D. solenoid
3. When particles from the Sun travel towards the Earth, the Earth’s magnetic field pulls them towards the
poles. These solar particles interact with particles in Earth’s atmosphere and can create a beautiful light
display in the sky. What is this light display commonly called?
A. aurora
B. geographic pole
C. radiation belt
D. solar flare
Unit Test A
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Unit 3
Name ______________________________________ Date _________
4. Which of the following best describes alternating current?
A. current that constantly turns on and off
B. current in which charges change direction
C. current that gains and loses electrons
D. current that increases and decreases in temperature
5. Which best describes electromagnetism?
A. the electrical component of a magnet
B. the flow of electricity between two magnets
C. the interaction between electricity and magnetism
D. the flow of a magnetic field between two electrons
6. The following instrument measures, detects, and determines the direction of a small electric current:
A student operating this instrument claims that this instrument has properties similar to an electromagnet.
Which of the following statements would best defend this claim?
A. When electric current flows through the wires, the voltage of the battery increases.
B. When electric current flows through the wires, the compass becomes demagnetized.
C. When the electric current flows through the wires, it causes the compass to become electrified.
D. When an electric current flows through the wires, it produces a magnetic field around the wire.
Unit Test A
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Module I • Assessment Guide
Unit 3
Name ______________________________________ Date _________
7. Candice learns that all magnets have two magnetic poles. Which of the following observations would best
support this statement?
A. When a bar magnet is cut in half, each half has a north pole and a south pole.
B. The north pole of a compass needle is attracted to the south pole of a bar magnet.
C. When an electric current flows through a wire, a magnetic field forms around the wire.
D. The strength of a horseshoe magnet’s magnetic field decreases as the magnet is pulled away from
another object.
8. What is the difference between charging by conduction and charging by induction?
A. During conduction, charges move between objects that briefly touch; during induction, charges move
between objects that are rubbed together.
B. During induction, charges move between objects that briefly touch; during conduction, charges move
between objects that are rubbed together.
C. During conduction, charges move between touching objects; during induction, charges are
redistributed within an object that is near another object.
D. During induction, charges move between touching objects; during conduction, charges are
redistributed within an object that is near another object.
9. Computers use binary digits to transmit information. What is this binary digit called?
A. binary code
B. bit
C. microprocessor
D. signal
Unit Test A
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Module I • Assessment Guide
Unit 3
Name ______________________________________ Date _________
10. The following image shows two conducting wires. Each wire is made of the same material and has the
same temperature:
Which of these wires has a greater electrical resistance?
A. Wire A
B. Wire B
C. Both wires will offer equal electrical resistance.
D. There is not enough information to determine.
11. During a lightning storm, the bottom of a cloud gains a strong negative electric charge. If you were
to measure the charge at the top of a tall metal pole directly under the cloud, what would you expect
to observe?
A. The top of the pole would have no charge.
B. The top of the pole would have a positive charge.
C. The top of the pole would have a negative charge.
D. The charge of the pole would not be affected by the charge of the cloud.
12. Which of the following correctly explains why people should not use frayed electrical cords?
A. Frayed electrical cords expose users to electric circuits, creating the risk of electric shock.
B. Frayed electrical cords are good conductors of electricity, increasing the likelihood of a uncontrolled
surge of electricity.
C. Frayed electrical cords use electricity very inefficiently, increasing the demand on power plants and
wasting energy resources.
D. Frayed electrical cords are series circuits, which means if one part of the circuit breaks, no current can
flow through the circuit.
Unit Test A
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Module I • Assessment Guide
Unit 3
Name ______________________________________ Date _________
13. Cara wants to make her school a safer place to be during a lightning storm. What could Cara do?
A. Remove circuit breakers from the school.
B. Dig a small pond in the back of the school.
C. Help mount a lightning rod on top of the school.
D. Design a plan to increase the height of the school.
14. Observe the following image:
What is the main purpose of this device in a computer system?
A. to process information in a computer
B. to input information into the computer
C. to store information inside of a computer
D. to display information processed by a computer
15. A science lab has copper wire coated with rubber tubing, a plastic vial, and a pair of cotton gloves. Which
of these materials is not an electrical insulator?
A. copper wire
B. cotton gloves
C. plastic
D. rubber tubing
Unit Test A
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Module I • Assessment Guide