Multiple Choice Question on Alternating Current and Voltage
1. 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
2. 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
3. How many degrees are there in π/3 rad?
A. 6°
B. 60°
C. 180°
D. 27°
Answer: Option B
4. 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
5. 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 wave forms is
A. 0°
B. 45°
C. 40°
D. none of the above
Answer: Option C
6. 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
7. 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
8. A 20 kHz pulse waveform consists of pulses that are 15 µ s wide. The duty cycle
A. is 1%
B. is 30%
C. is 100%
D. cannot be determined
Answer: Option B
9. 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
10. 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