**C1 Electric Circuits (Current, Resistance, Power)
Chapter 17**

**On-Line Quiz - 300 points**

**25 questions worth 12 points each**

1. Electric
resistance has units of:

a. ohm

b. (W-m)^{-1}

c. ampere

d. volt-ampere

e. (^{o}C)^{ -1}

f. W-m

2. Conductivity
has units of:

a. ohm

b. (W-m)^{ -1}

c. ampere

d. volt-ampere

e. (^{o}C)^{ -1}

f. W-m

3. Temperature
coefficient of resistivity has units of:

a. ohm

b. (W-m)^{ -1}

c. ampere

d. volt-ampere

e. (^{o}C)^{ -1}

f. W-m

4. Electric
current has units of:

a. ohm

b. (W-m)^{ -1}

c. ampere

d. volt-ampere

e. (^{o}C)^{ -1}

f. W-m

5. Resistivity
has units of:

a. ohm

b. (W-m)^{ -1}

c. ampere

d. volt-ampere

e. (^{o}C)^{ -1}

f. W-m

Page 2

6. Electric
power has units of:

a. ohm

b. (W-m)^{ -1}

c. ampere

d. volt-ampere

e. (^{o}C)^{ -1}

f. W-m

7. A car
battery

a. has an emf of 6 V consisting of one 6-V cell.

b. has an emf of 6 V consisting of three 2-V cells
connected in series.

c. has an emf of 6 V consisting of three 2-V cells
connected in parallel.

d. has an emf of 12 V consisting of six 2-V cells
connected in series.

e. has an emf of 12 V consisting of six 2-V cells
connected in parallel.

8. If you
connect two identical storage batteries together in parallel, and place them in
a circuit, the combination will provide

a. twice the voltage and twice the total charge
that one battery would.

b. twice the voltage and the same total charge
that one battery would.

c. the same voltage and twice the total charge
that one battery would.

d. half the voltage and half the total charge that
one battery would.

e. half the voltage and twice the total charge
that one battery would.

9. If you
connect two identical storage batteries together in series ("+" to
"-"), and place them in a circuit, the combination will provide

a. zero volts.

b. twice the voltage, and different currents will
flow through each.

c. twice the voltage, and the same current will
flow through each.

d. the same voltage, and different currents will
flow through each.

e. the same voltage and the same current will flow
through each.

10. The net
direction in which electrons flow through a circuit is

a. the conventional current

b. opposite the conventional current

11. A coulomb
per second is the same as

a. a watt.

b. an ampere.

c. a volt-second.

d. a volt per second.

12. A device
obeying Ohm's law must have a resistance which

a. is proportional to voltage

b. is proportional to current

c. is constant

d. is zero

Page 3

13. Consider
two copper wires. One has twice the
length and twice the cross-sectional area of the other. How do the resistances of these two wires
compare?

a. Both wires have the same resistance.

b. The longer wire has twice the resistance of the
shorter wire.

c. The longer wire has four times the resistance
of the shorter wire.

d. None of the above.

14. Negative
temperature coefficients of resistivity

a. do not exist.

b. exist in conductors.

c. exist in semiconductors.

d. exist in superconductors.

15. Which of
the above graphs indicates that the material is likely a semiconductor?

a. graph A

b. graph B

c. graph C

d. graph D

16. If the
resistance in a constant voltage circuit is doubled, the power dissipated by
that circuit will

a. increase by a factor of two.

b. increase by a factor of four.

c. decrease to one-half its original value.

d. decrease to one-fourth its original value.

Page 4

17. The
resistivity of most common metals

a. remains constant over wide temperature ranges.

b. increases as the temperature increases.

c. decreases as the temperature increases.

d. varies randomly as the temperature increases.

18. In the
graph shown, what physical quantity does the slope represent?

a. Current

b. Energy

c. Resistivity

d. Resistance

19. A 500-W
device is connected to a 100-V power source.
What current flows through this source?

a. 50,000 A

b. 0.2 A

c. 5 A

d. None of the above

20. A lamp uses
a 150-W bulb. If it is used at 120 V,
what current does it draw and what is its resistance?

21. Appliances
in the USA are designed to work on 110-120 V, whereas appliances in Europe operate
on 220-240 V. What would happen if you
tried to use a European electric shaver in this country?

a. It would probably work as well as it does in
Europe, since it is the power rating, not the voltage rating, that matters.

b. It would probably work as well as it does in
Europe, since it is the current rating, not the voltage rating, that matters.

c. It would barely work (or maybe not work at
all), since the voltage here is too low to push enough current through the
device.

d. It would probably overheat and burn up before
very long.

e. This question cannot be answered without
knowing the frequency used in Europe and in the USA, since this is the
parameter that matters most in any electrical device that operates on
alternating current.

Page 5

22. A battery
acquires and stores:

a. charge

b. potential

c. energy

d. all of the above

23. What do you
buy from the "power" company?

a. power

b. potential

c. current

d. energy

24. A negative
charge, if free, tries to move

a. from high potential to low potential

b. from low potential to high potential

c. toward infinity

d. away from infinity

25. Consider a
current moving from left to right through a resistor. Which end of the resistor is at higher potential?

a. left

b. right

c. indeterminate depends if current is charging a
battery or discharging a battery.