Unit 3 Test
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____
1. An ohm is the unit of measurement for:
a. electrical power.
b. voltage.
c. current.
d. resistance.
e. none of the above
____
2. If you look inside a stereo or telephone you will find a circuit board, which has wires printed on it
and is covered with little parts. Components called ____ are used to control current in the circuits on
the board.
a. resistors
b. wires
c. batteries
d. amperes
e. none of the above
____
3. If a microwave oven draws 11.0 amps of current when plugged into a 120.-volt outlet, what is its
power rating?
a. 1.32 kilowatts
b. 1.09 kilowatts
c. 132 watts
d. 109 watts
e. none of the above
____
4. What is the current in each resistor in the circuit?
a.
b.
c.
d.
e.
1
/3 ampere
1 ampere
3 amperes
9 amperes
none of the above
____
5. Positive electric charges:
a. attract both positive charges and negative charges.
b. repel both positive charges and negative charges.
c. attract positive charges and repel negative charges.
d. repel positive charges and attract negative charges.
e. none of the above
____
6. You use a 1200-watt hair dryer for 15 minutes and a 100-watt light bulb for one hour. How much
electricity do you use?
a. 300 watt-hours
b. 400 watt-hours
c. 500 watt-hours
d. 1,300 watt-hours
e. none of the above
____
7. In the circuit below, 3 amperes of current passes through the light bulb. The resistance of the light
bulb is 1.5 ohms. What is the voltage of the battery?
a.
b.
c.
d.
e.
1.5 volts
3 volts
4.5 volts
6 volts
none of the above
____
8. The electrical outlets in your home are wired in:
a. parallel circuits.
b. series circuits.
c. two-way circuits.
d. three-way circuits.
e. none of the above
____
9. The ability of an object to resist current is called:
a. potential difference.
b. electrical inertia.
c. alternating current.
d. electrical resistance.
e. none of the above
____ 10. Calculate the total resistance in the circuit below.
a.
b.
c.
d.
e.
1
/3 ohm
3 ohms
9 ohms
27 ohms
none of the above
____ 11. Kirchoff's current law applies to a parallel circuit because it states that:
a. current is the same everywhere throughout one entire circuit.
b. current is the same everywhere throughout branching circuit paths.
c. current stays the same as more branches are added to a parallel circuit.
d. all the current flowing into a branch point must flow out again.
e. none of the above
____ 12. What is the current in each resistor in the circuit below?
a.
b.
c.
d.
e.
1
/3 ampere
1 ampere
3 amperes
9 amperes
none of the above
____ 13. Which of the following statements best describes the difference between series and parallel circuits?
a. Series circuits are battery circuits and parallel circuits are generator circuits.
b. Series circuits have a single path and parallel circuits have two or more paths.
c. Series circuits are used in computers and parallel circuits are used in homes.
d. Series circuits have one switch in them and parallel circuits have two switches in
them.
e. none of the above
____ 14. What is the voltage drop across each resistor in the circuit below?
a.
b.
c.
d.
e.
2 volts
4 volts
6 volts
12 volts
none of the above
____ 15. Suppose you rub an inflated party balloon on a carpet, hold the balloon next to a wall, and discover
that it "sticks" to the wall. Why did the balloon stick to the wall?
a. The total charge on the balloon and wall becomes zero, so attraction between the
two can occur.
b. Like charges on the balloon and wall cause an attraction between the two.
c. Balloons contain a special "atomic glue" that allows them to cling to other objects.
d. Excess charge builds up on the balloon and electrostatic forces allow the
balloon and wall to be attracted to one another.
e. none of the above
____ 16. In an electrical circuit, a voltage difference:
a. supplies energy to make charges flow.
b. causes a short circuit.
c. is the term used for rate of charge flow.
d. wastes energy.
e. none of the above
____ 17. The current in a DC series circuit:
a. decreases to zero as it travels through the circuit.
b. is the same at all points in a circuit.
c. is greatest in the resistor with the highest resistance.
d. is greatest in the resistor with the lowest resistance.
e. none of the above
____ 18. Electrical conductivity describes:
a. the rate of charge flow.
b. the direction of charge flow.
c. the ability of an object to carry current.
d. the ability of a material to carry current.
e. none of the above
____ 19. What is the voltage drop across each resistor in the circuit below?
a.
b.
c.
d.
e.
1 volt
3 volts
4.5 volts
9 volts
none of the above
____ 20. Direct current (DC) and alternating current (AC) differ in:
a. the kind of charge flow.
b. the amount of charge flow.
c. the direction of charge flow.
d. the amount of energy per unit of charge.
e. none of the above
____ 21. What does a power company sell to its customers?
a. Power
b. Voltage
c. Current
d. Energy
e. none of the above
____ 22. In an electrical circuit, the term current refers to:
a. resistance.
b. potential difference.
c. flowing charges.
d. energy loss.
e. none of the above
Figure 3-1A
____ 23. Which of the circuit diagrams shown in Figure 3-1A is a parallel circuit?
a. I only
b. II only
c. III only
d. I and II only
e. none of the above
____ 24. Which of the circuit diagrams shown in Figure 3-1A is a series circuit?
a. I only
b. II only
c. III only
d. I and II only
e. none of the above
____ 25. Which of the following safety devices measure or react to specific levels of current?
a. Fuse
b. Circuit breaker
c. Ground fault circuit interrupter
d. All of the above
e. none of the above
Unit 3 Test
Answer Section
MULTIPLE CHOICE
1.
2.
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4.
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8.
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25.
D
A
A
C
D
B
D
A
D
C
D
C
B
C
D
A
B
D
B
C
D
C
D
C
D