Q 1. A sine wave with an rms value of 12 V is riding on a dc level of 18 V. The maximum value of the resulting waveform is
(A) 6 V
(B) 30 V
(C) 35 V
(D) 0 V
Answer: Option C
Q 2. A sine wave of 15 kHz is changing at a faster rate than a sine wave with a frequency of
(A) 25 kHz
(B) 12 kHz
(C) 18 kHz
(D) 1.3 MHz
Answer: Option B
Q 3. Sine wave A has a positive-going zero crossing at 45°. Sine wave B has a positive-going zero crossing at 60°. Which of the following statements is true?
(A) Wave A leads wave B by 15°
(B) Wave A lags wave B by 15°
(C) Wave A leads wave B by 105°
(D) Wave A lags wave B by 105°
Answer: Option A
Q 4. A ramp is the type of waveform characterized by a non-linear increase or decrease in voltage or current.
(A) True
(B) False
Answer: Option B
Q 5. If the rms current through a 6.8 kΩ resistor is 8 mA, the rms voltage drop across the resistor is
(A) 5.44 V
(B) 54.4 V
(C) 7.07 V
(D) 8 V
Answer: Option B
Q 6. A sinusoidal current has an rms value of 14 mA. The peak-to-peak value is
(A) 45.12 mA
(B) 16 mA
(C) 39.6 mA
(D) 22.6 mA
Answer: Option C
Q 7. The unit of frequency is the hertz.
(A) True
(B) False
Answer: Option A
Q 8. If the rms current through a 4.7 kΩ resistor is 4 mA, the peak voltage drop across the resistor is
(A) 4 V
(B) 18.8 V
(C) 26.6 V
(D) 2.66 V
Answer: Option C
Q 9. The conductive loop on the rotor of a simple two-pole, single-phase generator rotates at a rate of 400 rps. The frequency of the induced output voltage is
(A) 40 Hz
(B) 100 Hz
(C) 400 Hz
(D) Indeterminable
Answer: Option C
Q 10. If a sine wave goes through 10 cycles in 20 μs, the period is
(A) 20 μs
(B) 4 μs
(C) 2 μs
(D) 100 μs
Answer: Option C
Q 11. Amplitude is the maximum value of a voltage or current.
(A) True
(B) False
Answer: Option A
Q 12. How many degrees are there in π/3 rad?
(A) 6°
(B) 60°
(C) 180°
(D) 27°
Answer: Option B
Q 13. To produce an 800 Hz sine wave, a four-pole generator must be operated at
(A) 200 rps
(B) 400 rps
(C) 800 rps
(D) 1,600 rps
Answer: Option B
Q 14. A pulse waveform has a high time of 8 ms and a pulse width of 32 ms. The duty cycle is
(A) 25%
(B) 50%
(C) 1%
(D) 100%
Answer: Option A
Q 15. The angular position of a phasor represents the angle of the sine wave with respect to a reference.
(A) True
(B) False
Answer: Option A
Q 16. If the rms voltage drop across a 15 kΩ resistor is 16 V, the peak current through the resistor is
(A) 15 mA
(B) 1.5 mA
(C) 10 mA
(D) 1 mA
Answer: Option B
Q 17. The instantaneous value is the voltage or current value of a waveform at its peak.
(A) True
(B) False
Answer: Option B
Q 18. One sine wave has a positive-going zero crossing at 15° and another sine wave has a positive-going zero crossing at 55°. The phase angle between the two waveforms is
(A) 0°
(B) 45°
(C) 40°
(D) None of the above
Answer: Option C
Q 19. The duty cycle of a pulse waveform with a pulse width of 10 µs and a period of 100 µs is 25%.
(A) True
(B) False
Answer: Option B
Q 20. If the peak of a sine wave is 13 V, the peak-to-peak value is
(A) 6.5 V
(B) 13 V
(C) 26 V
(D) None of the above
Answer: Option C
Q 21. Periodic is characterized by a repetition at fixed time intervals.
(A) True
(B) False
Answer: Option A
Q 22. When a sine wave has a frequency of 100 Hz in 12 s it goes through
(A) 1/100 cycle
(B) 12 cycles
(C) 120 cycles
(D) 1,200 cycles
Answer: Option D
Q 23. A 20 kHz pulse waveform consists of pulses that are 15 μs wide. The duty cycle
(A) Is 1%
(B) Is 30%
(C) Is 100%
(D) Cannot be determined
Answer: Option B
Q 24. The designation rms means repetitions measured per second.
(A) True
(B) False
Answer: Option B
Q 25. The average value of a 12 V peak sine wave over one complete cycle is
(A) 0 V
(B) 1.27 V
(C) 7.64 V
(D) 6.37 V
Answer: Option A
Q 26. A square wave has a period of 60 μs. The first odd harmonic is
(A) 5 kHz
(B) 50 kHz
(C) 500 kHz
(D) 33.33 kHz
Answer: Option B
Q 27. A sine wave with a period of 4 ms is changing at a faster rate than a sine wave with a period of
(A) 0.0045 s
(B) 2 ms
(C) 1.5 ms
(D) 3,000 μs
Answer: Option A
Q 28. Two series resistors are connected to an ac source. If there are 7.5 V rms across one resistor and 4.2 V rms across the other, the peak source voltage is
(A) 16.54 V
(B) 1.65 V
(C) 10.60 V
(D) 5.93 V
Answer: Option A
Q 29. A waveform has a baseline of 3 V, a duty cycle of 20%, and an amplitude of 8 V. The average voltage value is
(A) 4 V
(B) 4.6 V
(C) 1.6 V
(D) 11 V
Answer: Option A
Q 30. A signal with a 400 μs period has a frequency of
(A) 250 Hz
(B) 2,500 Hz
(C) 25,000 Hz
(D) 400 Hz
Answer: Option B
Q 31. Average value of a sine wave is 0.707 times the peak value.
(A) True
(B) False
Answer: Option B
Q 32. A saw-tooth wave has a period of 10 ms. Its frequency is
(A) 10 Hz
(B) 50 Hz
(C) 100 Hz
(D) 1,000 Hz
Answer: Option C
Q 33. The length of a phasor represents the amplitude.
(A) True
(B) False
Answer: Option A
Q 34. A phasor represents
(A) The magnitude and a quantity direction
(B) The width of a quantity
(C) The phase angle
(D) The magnitude of a quantity
Answer: Option A
Q 35. A 1 kHz signal has a period of 1 ms.
(A) True
(B) False
Answer: Option A
Q 36. The average half-cycle value of a sine wave with a 40 V peak is
(A) 25.48 V
(B) 6.37 V
(C) 14.14 V
(D) 50.96 V
Answer: Option A
Q 37. Duty cycle is the characteristic of a pulse waveform that indicates the high time versus the low time.
(A) True
(B) False
Answer: Option B