Gibilisco Quiz 2

1. A positive electric pole:
A. Has a deficiency of electrons.
B. Has fewer electrons than the negative pole.
C. Has an excess of electrons.
D. Has more electrons than the negative pole

2. An EMF of one volt:
A. Cannot drive much current through a circuit.
B. Represents a low resistance.
C. Can sometimes produce a large current.
D. Drops to zero in a short time.

3. A potentially lethal electric current is on the order of:
A. 0.01 mA.
B. 0.1 mA.
C. 1 mA.
D. 0.1 A.

4. A current of 25 A is most likely drawn by:
A. A flashlight bulb.
B. A typical household.
C. A power plant.
D. A clock radio.

5. A piece of wire has a conductance of 20 siemens. Its resistance is:
A. 20 Ω.
B. 0.5 Ω.
C. 0.05 Ω.
D. 0.02 Ω.

6. A resistor has a value of 300 ohms. Its conductance is:
A. 3.33 millisiemens.
B. 33.3 millisiemens.
C. 333 microsiemens.
D. 0.333 siemens.

7. A mile of wire has a conductance of 0.6 siemens. Then three miles of the same
wire has a conductance of:
A. 1.8 siemens.
B. 1.8 Ω.
C. 0.2 siemens.
D. Not enough information has been given to answer this.

8. A 2-kW generator will deliver approximately how much current, reliably, at 117
V?
A. 17 mA.
B. 234 mA.
C. 17 A.
D. 234 A.

9. A circuit breaker is rated for 15 A at 117 V. This represents approximately how
many kilowatts?
A. 1.76.
B. 1760.
C. 7.8.
D. 0.0078.

10. You are told that a certain air conditioner is rated at 500 Btu. What is this in
kWh?
A. 147.
B. 14.7.
C. 1.47.
D. 0.147.

11. Of the following energy units, the one most often used to define electrical
energy is:
A. The Btu.
B. The erg.
C. The foot pound.
D. The kilowatt hour.

12. The frequency of common household ac in the U.S. is:
A. 60 Hz.
B. 120 Hz.
C. 50 Hz.
D. 100 Hz.

13. Half-wave rectification means that:
A. Half of the ac wave is inverted.
B. Half of the ac wave is chopped off.
C. The whole wave is inverted.
D. The effective value is half the peak value.

14. In the output of a half-wave rectifier:
A. Half of the wave is inverted.
B. The effective value is less than that of the original ac wave.
C. The effective value is the same as that of the original ac wave.
D. The effective value is more than that of the original ac wave.

15. In the output of a full-wave rectifier:
A. The whole wave is inverted.
B. The effective value is less than that of the original ac wave.
C. The effective value is the same as that of the original ac wave.
D. The effective value is more than that of the original ac wave.

16. A low voltage, such as 12 V:
A. Is never dangerous.
B. Is always dangerous.
C. Is dangerous if it is ac, but not if it is dc.
D. Can be dangerous under certain conditions.

17. Which of these can represent magnetomotive force?
A. The volt-turn.
B. The ampere-turn.
C. The gauss.
D. The gauss-turn.

18. Which of the following units can represent magnetic flux density?
A. The volt-turn.
B. The ampere-turn.
C. The gauss.
D. The gauss-turn.

19. A ferromagnetic material:
A. Concentrates magnetic flux lines within itself.
B. Increases the total magnetomotive force around a current-carrying wire.
C. Causes an increase in the current in a wire.
D. Increases the number of ampere-turns in a wire.

20. A coil has 500 turns and carries 75 mA of current. The magnetomotive force
will be:
A. 37,500 At.
B. 375 At.
C. 37.5 At.
D. 3.75 At.

Gibilisco Quiz 1

1. The atomic number of an element is determined by:

A. The number of neutrons.

B. The number of protons.

C. The number of neutrons plus the number of protons.

D. The number of electrons.

2. The atomic weight of an element is approximately determined by:

A. The number of neutrons.

B. The number of protons.

C. The number of neutrons plus the number of protons.

D. The number of electrons.

3. Suppose there is an atom of oxygen, containing eight protons and eight

neutrons in the nucleus, and two neutrons are added to the nucleus. The resulting

atomic weight is about:

A. 8.

B. 10.

C. 16.

D. 18.

4. An ion:

A. Is electrically neutral.

B. Has positive electric charge.

C. Has negative electric charge.

D. Might have either a positive or negative charge.

5. An isotope:

A. Is electrically neutral.

B. Has positive electric charge.

C. Has negative electric charge.

D. Might have either a positive or negative charge.

6. A molecule:

A. Might consist of just a single atom of an element.

B. Must always contain two or more elements.

C. Always has two or more atoms.

D. Is always electrically charged.

7. In a compound:

A. There can be just a single atom of an element.

B. There must always be two or more elements.

C. The atoms are mixed in with each other but not joined.

D. There is always a shortage of electrons.

8. An electrical insulator can be made a conductor:

A. By heating.

B. By cooling.

C. By ionizing.

D. By oxidizing.

9. Of the following substances, the worst conductor is:

A. Air.

B. Copper.

C. Iron.

D. Salt water.

10. Of the following substances, the best conductor is:

A. Air.

B. Copper.

C. Iron.

D. Salt water.

11. Movement of holes in a semiconductor:

A. Is like a flow of electrons in the same direction.

B. Is possible only if the current is high enough.

C. Results in a certain amount of electric current.

D. Causes the material to stop conducting.

12. If a material has low resistance:

A. It is a good conductor.

B. It is a poor conductor.

C. The current flows mainly in the form of holes.

D. Current can flow only in one direction.

13. A coulomb:

A. Represents a current of one ampere.

B. Flows through a 100-watt light bulb.

C. Is one ampere per second.

D. Is an extremely large number of charge carriers.

14. A stroke of lightning:

A. Is caused by a movement of holes in an insulator.

B. Has a very low current.

C. Is a discharge of static electricity.

D. Builds up between clouds.

15. The volt is the standard unit of:

A. Current.

B. Charge.

C. Electromotive force.

D. Resistance.

16. If an EMF of one volt is placed across a resistance of two ohms, then the

current is:

A. Half an ampere.

B. One ampere.

C. Two amperes.

D. One ohm.

17. A backwards-working electric motor is best described as:

A. An inefficient, energy-wasting device.

B. A motor with the voltage connected the wrong way.

C. An electric generator.

D. A magnetic-field generator.

18. In some batteries, chemical energy can be replenished by:

A. Connecting it to a light bulb.

B. Charging it.

C. Discharging it.

D. No means known; when a battery is dead, you have to throw it away.

19. A changing magnetic field:

A. Produces an electric current in an insulator.

B. Magnetizes the earth.

C. Produces a fluctuating electric field.

D. Results from a steady electric current.

20. Light is converted into electricity:

A. In a dry cell.

B. In a wet cell.

C. In an incandescent bulb.

D. In a photovoltaic cell.