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- Question
Why is ac current transfer more effective than dc current transfer over long distances?
Options- 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
- Correct Answer
- due to step-up and step-down transformers reducing I2R losses
- 1. The distance that a signal's energy can travel in the time it takes for one cycle to occur is called the signal's:
Options- A. amplitude
- B. frequency
- C. wavelength
- D. period Discuss
- 2. A test equipment item that has the ability to produce either square, triangular, or sawtooth waveforms is called:
Options- A. a function generator
- B. a radio frequency generator
- C. an audio frequency generator
- D. a frequency meter or counter Discuss
- 3. What is the name of a device used to directly measure the frequency of a periodic wave?
Options- A. oscilloscope
- B. frequency meter or counter
- C. audio frequency generator
- D. radio frequency generator Discuss
- 4. 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:
Options- A. time/cm control
- B. position control
- C. intensity control
- D. volts/cm control Discuss
- 5. If a sine wave signal is 100 mV peak-to-peak, how many volts would be measured by a voltmeter?
Options- A. 14.14 mV
- B. 35.4 mV
- C. 63.7 mV
- D. 70.7 mV Discuss
- 6. A rectangular wave that has a duty cycle of 50 percent could be called a:
Options- A. c wave
- B. sawtooth wave
- C. square wave
- D. triangle wave Discuss
- 7. If a waveform period is determined to be 10 microseconds in duration, what is the frequency of the signal?
Options- A. 100 Hz
- B. 1000 Hz
- C. 10 kHz
- D. 100 kHz Discuss
- 8. Which control should be moved to display more cycles of a signal on an oscilloscope?
Options- 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 Discuss
- 9. What is the peak-to-peak current value when an ammeter measures a 20 mA value?
Options- A. 14 mA
- B. 28 mA
- C. 40 mA
- D. 57 mA Discuss
- 10. If a voltmeter measures a sine wave as 500 mV, what would be its average value?
Options- A. 159.0 mV
- B. 318.5 mV
- C. 353.5 mV
- D. 451.0 mV Discuss
Alternating Current vs Direct Current problems
Search Results
Correct Answer: wavelength
Correct Answer: a function generator
Correct Answer: frequency meter or counter
Correct Answer: volts/cm control
Correct Answer: 35.4 mV
Correct Answer: square wave
Correct Answer: 100 kHz
Correct Answer: time/cm to a higher setting
Correct Answer: 57 mA
Correct Answer: 451.0 mV
Explanation:
Some AC Voltage Conversion:
Peak to rms: multiply peak by 0.707.
Peak to average: multiply peak by 0.637.
Rms to peak: multiply rms by 1.414.
Rms to average: multiply rms by 0.9.
Average to rms: multiply avg by 1.111.
Average to peak: multiply avg by 1.567.
Mostly voltmeter shows rms value. So, Vav = 0.9*Vrms
= 0.9*500.
= 450mV ~ [D] 451 mV.
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