# Gibilisco:Chapter 2 - Electrical Units

20 Questions | Total Attempts: 797  Settings  This is the MCQs for Gibilisco:CHAPTER 2 - ELECTRICAL UNITS

• 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.

• 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

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