Deck 11: Alternating Current

Question 1

The ____ value must be found when a sine wave AC voltage is changed into direct current.

A) average
B) peak
C) peak-to-peak
D) RMS

Answer 1

A

Question 2

A ____ wave is one in which the voltage rises at a constant rate with respect to time.

A) peak
B) sine
C) square
D) linear

Answer 2

D

Question 3

A ____-wave rectifier is one that changes both the positive half and the negative half of the AC wave form into DC.

A) half
B) full
C) square
D) linear

Answer 3

B

Question 4

Each completed wave form of a sine wave is called a(n) ____.

A) frequency
B) hertz
C) cycle
D) farad

Question 5

The skin effect is proportional to the ____. As the ____ increases, the skin effect increases.

A) hertz
B) cycle
C) frequency

Question 6

The most common frequency used in electrical generation in the United States and Canada is ____ hertz.

A) 60
B) 90
C) 180
D) 360

Question 7

The average voltage is ____ the peak, or maximum, value of the wave form and to the length of time it is on as compared to the length of time it is off.

A) the same as
B) the square root of
C) the square of
D) proportional to

Question 8

____ can be produced in AC circuits only when both current and voltage are either positive or negative.

A) Watts
B) True power
C) RMS
D) a or b

Question 9

The AC voltage that will produce the same amount of power as a like value of DC voltage is called the ____ value.

A) average
B) peak
C) peak-to-peak
D) RMS

Question 10

The pulses of pulsating direct current are often referred to as ____.

A) ripple
B) current
C) flow
D) wave

Question 11

Square waves are generally produced by electronic devices called ____.

A) megohmmeters
B) galvanometers
C) oscillators
D) generators

Question 12

In DC circuits, there is only one basic type of load, which is ____.

A) inductive
B) amperage
C) resistive
D) reversing

Question 13

The ____ value is measured from the maximum value in the positive direction to the maximum value in the negative direction.

A) average
B) peak
C) peak-to-peak
D) RMS

Question 14

The ____ wave is produced by all rotating machines.

A) sine
B) linear
C) triangle
D) square

Question 15

Peak-to-peak, peak, RMS, and average are measurements of ____ associated with sine waves.

A) wattage and resistance
B) amperage and resistance
C) voltage and resistance
D) voltage and amperage

Question 16

In the early days of electric power generation, Thomas Edison proposed powering the country with ____.

A) low-voltage alternating current
B) low-voltage direct current
C) high-voltage alternating current
D) high-voltage direct current

Question 17

The ____ is measured from zero to the highest value obtained in either the positive or negative direction.

A) average
B) peak
C) peak-to-peak
D) RMS

Question 18

In a sine wave, the number of complete cycles that occur in one second is called a ____.

A) frequency
B) hertz
C) cycle
D) farad

Question 19

____ cable is less affected by the skin effect.

A) Braided
B) Solid
C) Stranded

Question 20

____ waves are so named because the voltage at any point along the wave form is equal to the maximum, or peak, value times the sine of the angle of rotation.

A) Linear
B) Sine
C) Square
D) Triangle

Question 21

The most common of all AC waves is the ____________________ wave.

Question 22

Probably the greatest single advantage of alternating current is that it can be ____________________.

Question 23

____ is the maximum height reached by a wave form.

A) Ripple
B) Root-mean-square
C) Amplitude
D) Linear wave

Question 24

Frequency is measured in ____________________.

Question 25

A ____________________ is used to change alternating current into direct current.

Question 26

Thomas Edison's main competitor, Nikola Tesla, believed that _________________________ was impractical for large-scale electrical transmission applications.

Question 27

In resistive loads, the ____________________, or watts, is the product of the volts times the amps.

Question 28

Alternating current can be _________________________ for the purpose of transmission and then be _________________________ when it is to be used by a device.

Question 29

The _________________________ occurs when alternating current induces eddy currents into a conductor, which causes the electrons to be repelled toward the outer surface of the conductor.

Question 30

A ____________________ wave reaches its peak positive voltage at 90 degrees, its maximum negative voltage at 270 degrees, and has a total of 360 electrical degrees.

Question 31

The advantage of high-voltage transmission is that less ____________________ is required to produce the same amount of power.

Question 32

RMS stands for ______________________________, which is an abbreviation for the square root of the mean of the square of the instantaneous currents.

Question 33

____________________ loads are loads that produce heat and have the current and the voltage in phase with each other.

Question 34

____________________ direct current occurs when the voltage wave form turns on and off but never changes direction, which means it never reverses direction.

Question 35

There are three basic types of AC loads: resistive, inductive, and ____________________.