Alternating Current and Voltage

MCQsQuestion.com has 29 Question/Answers about Topic Alternating Current and Voltage

The magnitude of an alternation that varies from zero is called its _______.

The magnitude of an alternation that varies from zero is called its _______.
  • A. altitude
  • B. polarity
  • C. attitude
  • D. amplitude
  • Correct Answer: Option D

All periodic frequencies are derived by combining higher frequency ______________ called harmonics.

All periodic frequencies are derived by combining higher frequency ______________ called harmonics.
  • A. sine waves
  • B. pulse waves
  • C. square waves
  • D. sawtooth waves
  • Correct Answer: Option A

The frequency of the repetitive pulse waveform in the given circuit equals ___.

The frequency of the repetitive pulse waveform in the given circuit equals ___.
  • A. 500 Hz
  • B. 50 Hz
  • C. 100 Hz
  • D. 125 Hz
  • Correct Answer: Option C

The peak voltage across R2 in the given circuit equals _____.

The peak voltage across R2 in the given circuit equals _____.
  • A. 7.2 V
  • B. 10.18 V
  • C. 8.8 V
  • D. 8 V
  • Correct Answer: Option B

The phase angle between the two waveforms in the given circuit equals _____.

The phase angle between the two waveforms in the given circuit equals _____.
  • A. 75°
  • B. 15°
  • C. 105°
  • D. 45°
  • Correct Answer: Option B

A peak current of 12.5 mA is equivalent to ___.

A peak current of 12.5 mA is equivalent to ___.
  • A. an rms value of 25 mA
  • B. an average value of 12.5 mA
  • C. a peak-to-peak value of 6.25 mA
  • D. an average value of 7.96 mA
  • Correct Answer: Option D

An rms voltage of 5 V is equivalent to ___.

An rms voltage of 5 V is equivalent to ___.
  • A. 14.14 V peak-to-peak
  • B. a peak value of 5 V
  • C. 10 V peak-to-peak
  • D. an average value of 7.07 V
  • Correct Answer: Option A

Increasing the number of turns in a conductor loop in a basic generator will ___.

Increasing the number of turns in a conductor loop in a basic generator will ___.
  • A. increase the generator's output voltage amplitude
  • B. increase the generator's output frequency
  • C. decrease the generator's output voltage amplitude
  • D. decrease the generator's output frequency
  • Correct Answer: Option A

Increasing the number of magnetic poles in a basic generator will ___.

Increasing the number of magnetic poles in a basic generator will ___.
  • A. increase the generator's output voltage amplitude
  • B. increase the generator's output frequency
  • C. decrease the generator's output voltage amplitude
  • D. decrease the generator's output frequency
  • Correct Answer: Option B

The frequency of the sine wave in the given circuit equals ___.

The frequency of the sine wave in the given circuit equals ___.
  • A. 4 kHz
  • B. 800 Hz
  • C. 20 kHz
  • D. 250 Hz
  • Correct Answer: Option C

If a sine wave’s period equals 50 ms, its frequency equals _____.

If a sine wave’s period equals 50 ms, its frequency equals _____.
  • A. 20 Hz
  • B. 0.02 Hz
  • C. 50 Hz
  • D. 50 kHz
  • Correct Answer: Option A

If a sine wave’s frequency equals 25 MHz, its period equals _____.

If a sine wave’s frequency equals 25 MHz, its period equals _____.
  • A. 25 µs
  • B. 25 ms
  • C. 4 µs
  • D. 40 ns
  • Correct Answer: Option D

If a wave has frequency of 2 Hz, it has a period of ?

If a wave has frequency of 2 Hz, it has a period of ?
  • A. 1s
  • B. 1/2 s
  • C. 2.5s
  • D. 2s
  • Correct Answer: Option B

A single-phase induction motor

A single-phase induction motor
  • A. is self-starting
  • B. operates at a fixed speed
  • C. is less reliable than a three-phase synchronous motor
  • D. none of the above
  • Correct Answer: Option D

In both induction and synchronous ac motors

In both induction and synchronous ac motors
  • A. the operating speed is very steady
  • B. the stator magnetic field is stationary
  • C. the stator magnetic field rotates
  • D. the "squirrel cage" forms the rotor
  • Correct Answer: Option C
Page 1 of 212