Deck 16: Alternating Current

Question 1

If an AC waveform is rectified and converted into DC, the voltage value that results is the _____ value.

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

Answer 1

A

Question 2

What is the unit of measure for the power delivered to the load in a DC circuit?

A) hertz
B) volt-amperes
C) VARs
D) watts

Answer 2

D

Question 3

The maximum point of a waveform is called the _____.

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

Answer 3

B

Question 4

In a DC circuit, the product of volts times the amperes is called the _____ power.

A) apparent
B) reactive
C) true
D) inductive

Question 5

What type of load contains pure resistance?

A) capacitive
B) inductive
C) reactive
D) resistive

Question 6

When AC voltage is rectified and converted into DC, the resulting waveform is normally not pure, flat DC. The pulses that occur are called _____.

A) harmonics
B) cosines
C) ripples
D) peaks

Question 7

The number of cycles completed in one second is called a _____.

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

Question 8

Both AC and DC can be transformed.

Question 9

A term used to indicate the same value as the RMS value is the _____ value.

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

Question 10

Square waves are generally produced by electronic devices called _____.

A) converters
B) alternators
C) oscillators
D) rectifiers

Question 11

Frequency is measured in _____.

A) watts
B) hertz
C) amperes
D) voltage

Question 12

What is the most common of all AC waveforms?

A) triangle
B) sine
C) pulsating
D) cosine

Question 13

What is the average voltage of a full-wave rectified 240 V RMS AC voltage?

A) 216.17 V
B) 252.88 V
C) 276.32 V
D) 332.75 V

Question 14

The amplitude of a waveform is measured from _____.

A) peak-to-peak
B) zero to the highest value obtained in either direction
C) zero to the RMS level
D) zero to the effective level

Question 15

The square root of the mean of the square of the instantaneous currents is known as the _____.

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

Question 16

Rotating machines normally produce a waveform called a _____ wave.

A) cosine
B) linear
C) sine
D) pulsating

Question 17

What is the peak voltage of a 277 V RMS AC voltage?

A) 391.68 V
B) 434.85 V
C) 576.45 V
D) 695.90 V

Question 18

Each complete waveform of 360 ° is called a _____.

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

Question 19

What type of AC waveform features voltage rising at a constant rate with respect to time?

A) cosine
B) linear
C) sine
D) pulsating

Question 20

What is the RMS value of an AC voltage that has a 480 V peak?

A) 278.72 V
B) 305.76 V
C) 339.46 V
D) 453.53 V

Question 21

To help overcome the problem of skin effect in high-frequency circuits, conductors with a large amount of _______________ must be used.

Question 22

When current rises and falls at the same rate as the voltage and reverses the direction of flow when the voltage reverses polarity, the current is said to be _____ with the voltage.

A) in phase
B) out of phase
C) in leading phase
D) in lagging phase

Question 23

The_____ effect occurs when AC induces eddy currents into the conductor, which cause the electrons to be repelled toward the outer surface of the conductor.

A) insulation
B) phasing
C) skin
D) resistance