IndiaBix_Alternating Current vs Direct Current

What are the two main applications for ac?

A. direct, pulsating
B. electric, magnetic
C. power, information
D. static, dynamic

C

The distance that a signal's energy can travel in the time it takes for one cycle to occur is called the signal's:

A. amplitude
B. frequency
C. wavelength
D. period

C

One oscilloscope selector knob that allows the major and minor divisions of the graticule to be used to determine a signal amplitude value is called the:

A. time/cm control
B. position control
C. intensity control
D. volts/cm control

D

If current varies periodically from zero to a maximum, back to zero, and then repeats, the signal is:

A. direct
B. alternating
C. pulsating
D. repetitive

C

What voltage will an ac voltmeter display?

A. rms
B. average
C. peak
D. peak-to-peak

A

What is the peak value of a household appliance that uses a 230 V ac source?

A. 163 V
B. 230 V
C. 325 V
D. 480 V

C

What is the waveform period difference between the 60 Hz electricity used in this country and the 50 Hz used in Europe?

A. 3 ms
B. 16 ms
C. 4 ms
D. 20 ms

A

Test equipment selection enables the technician to both generate signals and:

A. change circuit conditions
B. inject signals
C. sense circuit conditions
D. change signal frequencies

C

Why is ac current transfer more effective than dc current transfer over long distances?

A. due to the height of power lines
B. due to the use of ac generators
C. due to step-up and step-down transformers reducing I2R losses
D. due to very high voltages

C

A sine wave reaches maximum positive voltage at:

A. 90°
B. 0°
C. -90°
D. 360°

A

Which percentages of full-amplitude rise time are used for a pulse wave?

A. 0 to 50 percent
B. 0 to 100 percent
C. 5 to 95 percent
D. 10 to 90 percent

D

What is the average value of a 12 V peak wave?

A. 3.82 V
B. 4.24 V
C. 7.64 V
D. 9.42 V

C

A test equipment item that has the ability to produce either square, triangular, or sawtooth waveforms is called:

A. a function generator
B. a radio frequency generator
C. an audio frequency generator
D. a frequency meter or counter

A

The current is flowing in what direction?

A. clockwise
B. counterclockwise
C. in both directions at the same time
D. 50% of the time clockwise and 50% of the time counterclockwise

D

What does the CRT oscilloscope display?

A. voltage and period
B. current and frequency
C. rms voltage and current
D. frequency and voltage

A

Power companies supply ac, not dc, because:

A. it is easier to transmit ac
B. there is no longer a need for dc
C. dc is more dangerous
D. there are not enough batteries

A

If a waveform period is determined to be 10 microseconds in duration, what is the frequency of the signal?

A. 100 Hz
B. 1000 Hz
C. 10 kHz
D. 100 kHz

D

The phase difference between sine waves of different frequencies is:

A. equal to their frequency differences
B. the difference in their fixed time displacement
C. the same throughout time
D. constantly changing

B

If a sine wave signal is 100 mV peak-to-peak, how many volts would be measured by a voltmeter?

A. 14.14 mV
B. 35.4 mV
C. 63.7 mV
D. 70.7 mV

B

What term expresses the frequency of a rectangular wave?

A. Hz
B. period
C. PRF
D. PRT

C

AC effective voltage is named:

A. average
B. peak
C. peak-to-peak
D. root mean square

D

If a voltmeter measures a sine wave as 500 mV, what would be its average value?

A. 159.0 mV
B. 318.5 mV
C. 353.5 mV
D. 451.0 mv

D

One adjustable knob on the oscilloscope that allows the trace to be aligned with a reference graticule is called the:

A. position control
B. focus control
C. intensity control
D. volts/cm control

A

Signal comparisons may be most easily seen when using which item of test equipment?

A. spectrum analyzer
B. multimeter
C. function generator
D. dual trace oscilloscope

D

The magnitude that an alternation varies from zero is called its:

A. altitude
B. amplitude
C. attitude
D. polarity

B

The power that is distributed from a power plant to your home is:

A. high voltage to high voltage
B. low voltage to high voltage
C. high voltage to low voltage
D. low voltage to low voltage

C

A rectangular wave that has a duty cycle of 50 percent could be called a:

A. c wave
B. sawtooth wave
C. square wave
D. triangle wave

C

A triangle wave consists of repeating:

A. positive ramps only
B. negative ramps only
C. positive and negative ramps of equal value
D. positive and negative ramps of unequal value

C

What is the name of a device used to directly measure the frequency of a periodic wave?

A. oscilloscope
B. frequency meter or counter
C. audio frequency generator
D. radio frequency generator

B

Which control should be moved to display more cycles of a signal on an oscilloscope?

A. horizontal position to left or right
B. volts/cm to a smaller number
C. vertical position to top or bottom
D. time/cm to a higher setting

D

What is the name of a device that converts sound waves to electrical waves?

A. an amplifier
B. an antenna
C. a filter
D. a microphone

D

If the frequency of a radio wave is increased, then its wavelength will:

A. increase
B. decrease
C. remain the same
D. cannot tell

B

What is the rms voltage value of an ac signal whose peak oscilloscope display uses 3 major divisions above the zero setting? (V/cm = 5)

A. 5.3 V
B. 10.6 V
C. 15.0 V
D. 21.2 V

B

What is the peak-to-peak current value when an ammeter measures a 20 mA value?

A. 14 mA
B. 28 mA
C. 40 mA
D. 57 mA

D

How long would it take to transmit an electromagnetic wave to a receiving antenna 1,000 miles away?

A. 5.38 ms
B. 10.8 ms
C. 53.8 ms
D. 108 ms

A

What is the waveform period of a square wave signal that horizontally covers 3 major divisions per cycle? (time/cm = 50 ms)

A. 50 ms
B. 100 ms
C. 150 ms
D. 200 ms

C

A sine wave has:

A. four quadrants
B. two alternations
C. one period
D. all of the above

D

What is the peak-to peak voltage of a 56 Vrms ac voltage?

A. 158 V
B. 164 V
C. 82 V
D. 79 V

A

One oscilloscope selector knob that allows the major and minor divisions of the graticule to be used to determine a waveform period is called a:

A. focus control
B. time/cm control
C. intensity control
D. volts/cm control

B

What is the period of a 16 MHz sine wave?

A. 196 ns
B. 62.5 ns
C. 31.25 ns
D. 19.9 ns

B