Download Name Date Section Electricity and Magnetism Unit Test Physical

Name
Electricity and Magnetism Unit Test
Physical Science
Date
Section
Multiple Choice
1. Distinguish between a conductor and an insulator.
A. A conductor repels charged objects; an insulator attracts them.
B.
A conductor cannot produce static electricity; an insulator can.
C.
A conductor allows electrons to move easily through it; an insulator does not.
D.
A conductor can be plastic, wood, or glass; an insulator is always metal.
2. Name one thing that is necessary to keep current flowing.
A. an unbroken path for electrons to follow
B.
a circuit breaker
C.
static electricity
D.
a moist chemical paste
3. What observation about the current in a metal conductor was the basis for Ohm's law?
A. Current depends only on the conductor's resistance.
B.
Current depends on resistance and potential difference.
C.
Current is unrelated to resistance.
D.
The higher the current, the higher the resistance.
4. Explain why a whole string of holiday lights may not work if one bulb is burned out.
A. The lights are connected in a parallel circuit.
B.
The burned-out bulb acts as a semiconductor.
C.
The burned-out bulb trips the circuit breaker in your home electrical system.
D.
The lights are wired together in a series circuit.
5. What is the function of a circuit breaker box?
A.
to protect against fires caused by overloading circuits
B.
to reduce the amount of energy used by household appliances
C.
to reduce the voltage of the electricity that comes into your home
D. to prevent lightbulbs from burning out
6. When two negative charges are brought close together, they will ______.
A. repel
B.
attract
C.
neither attract nor repel
D.
ground
7. An example of a good insulator is _______.
A. copper
B.
silver
C.
wood
D.
salt water
8. Electrical energy is measured in ______.
A. volts
B.
newtons
C.
kilowatts
D.
kilowatt-hours
9. Where on a magnet are magnetic forces strongest?
A.
at its north pole
B.
in the center
C.
at both ends
D.
at its south pole
10. What is the name for the region around a magnet where magnetic forces act?
A. the north pole
B.
a compass
C.
the magnetic domain
D.
the magnetic field
11. Why does the needle of a compass always point north?
A. It has been electronically programmed to do so.
B.
It aligns with Earth's magnetic field lines.
C.
It is attracted to a large metal pole at the top of Earth.
D.
There are more magnetic materials in northern regions of Earth.
12. How is the magnetism of an electromagnet turned on and off?
A. with a galvanometer
B.
by adding more turns in the coil
C.
by reversing the direction of current
D.
by controlling the flow of current through the coil
13. Which parts are present in an electric motor?
A. an electromagnet and a permanent fixed magnet
B.
an ammeter and a voltmeter
C.
a generator and a circuit breaker
D.
a galvanometer and an electromagnet
14. What is a superconductor?
A. a fast train that uses magnetism to operate
B.
a material that has no resistance when cooled to a certain temperature
C.
a magnet that induces a current in a conductor
D.
any supercooled conductor
15. As the distance between two magnetic poles decreases, the magnetic force ______.
A. remains constant
B.
changes unpredictably
C.
increases
D.
decreases
Matching
A. Current
B. Voltage
C. Resistance
D. Electrons
E. Protons
F. Electric Power
G. Electric Energy
H. Circuit Breaker/Fuse
16. Difference in the number of electrons
17. Opposes the flow of electricity
18. Negatively charged particles
19. Flow of electricity
20. Positively charged particle
21. Rate at which an electrical device converts energy from one form to another
22. Device used to protect from overloaded circuits
23. Measure of the amount of electric power actually consumed over time
Short Answer
24. Draw the following circuits containing only one battery and be sure to label them.
- A series circuit with two light bulbs,
- A parallel circuit with three light bulbs,
- A circuit with one resistors, a motor, and a switch,
- A circuit with one light bulb,
- And a circuit with a resistor and a light bulb in series.
Which one will provide the most power to its “working” mechanism (i.e. which light bulb
will be brightest, second brightest, etc.)? Why does a parallel circuit work even if one of the
light bulbs doesn’t work? Why does a series circuit stop working when a light bulb stops
working?
25. What does our magnetic field do for us and in turn what could happen if it was to fail?
Problems
Show all work!!
V=IR
26. Calculate the voltage difference in a circuit with a resistance of 25 ohms if the current in
the circuit is 0.5 A.
Answer
Show work:
27. A current of 0.5 A flows in a 60 W light bulb when the voltage difference between the
ends of the filament is 120 V. What is the resistance of the filament?
Answer
Show work:
28. A toy car with a resistance of 20 ohms is connected to a 3V battery. How much current
flows in the car?
Answer
Show work:
Works Cited
Glencoe Online. “Physical Science”.
<http://www.glencoe.com/sec/science/lep_science/physical_science/tutor/quizzes/test2
2.html>.
<http://www.glencoe.com/sec/science/lep_science/physical_science/tutor/quizzes/test2
1.html>. Web. 20 July 2014.
Physical Science.
<http://albphysicalscience.weebly.com/uploads/9/0/3/1/903172/electricity_test_review
_answers.pdf>. Web. 20 July 2014.