Alternating Current And Voltage MCQs with Explanations

Understanding the Problem: We have two resistors in series connected to an AC voltage source. We know the RMS (Root Mean Square) voltage across each resistor. We need to find the peak voltage of the source. Key Concepts: RMS Voltage: This is the effective voltage of an AC signal, equivalent to a DC voltage that would produce the same heating effect. Peak Voltage: This is the maximum voltage reached by the AC signal during each cycle. The relationship between peak voltage (V peak ) and RMS voltage (V rms ) is: V peak = V rms * √2 Series Circuit: In a series circuit, the current is the same through all components. The voltages across the resistors add up to the source voltage. Steps to Solve: 1. Find the total RMS voltage: Since the resistors are in series, the total RMS voltage is the sum of the RMS voltages across each resistor. So, V rms(total) = 7.5 V + 4.2 V = 11.7 V 2. Calculate the peak voltage: Use the formula V peak = V rms * √2. So, V peak = 11.7 V * √2 ≈ 11.7 V * 1.414 ≈ 16.54 V Therefore, the correct answer is Option A: 16.54 V

400 rps is the correct answer to “To produce an 800 Hz sine wave, a four-pole generator must be operated at”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

Wave A leads wave B by 15° is the correct answer to “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”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

False is the correct answer to “A ramp is the type of waveform characterized by a non-linear increase or decrease in voltage or current.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

True is the correct answer to “Amplitude is the maximum value of a voltage or current.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

25.48 V is the correct answer to “The average half-cycle value of a sine wave with a 40 V peak is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

12 kHz is the correct answer to “A sine wave of 15 kHz is changing at a faster rate than a sine wave with a frequency of”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

1,200 cycles is the correct answer to “When a sine wave has a frequency of 100 Hz in 12 s it goes through”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

2 µs is the correct answer to “If a sine wave goes through 10 cycles in 20 µs, the period is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

The magnitude and a quantity direction is the correct answer to “A phasor represents”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

4 V is the correct answer to “A waveform has a baseline of 3 V, a duty cycle of 20%, and an amplitude of 8 V. The average voltage value is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

True is the correct answer to “A 1 kHz signal has a period of 1 ms.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

0.0045 s is the correct answer to “A sine wave with a period of 4 ms is changing at a faster rate than a sine wave with a period of”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

False is the correct answer to “The instantaneous value is the voltage or current value of a waveform at its peak.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

2,500 Hz is the correct answer to “A signal with a 400 µs period has a frequency of”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

39.6 mA is the correct answer to “A sinusoidal current has an rms value of 14 mA. The peak-to-peak value is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

26 V is the correct answer to “If the peak of a sine wave is 13 V, the peak-to-peak value is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

400 Hz is the correct answer to “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”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

35 V is the correct answer to “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”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

False is the correct answer to “Average value of a sine wave is 0.707 times the peak value.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

50 kHz is the correct answer to “A square wave has a period of 60 µs. The first odd harmonic is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

True is the correct answer to “Periodic is characterized by a repetition at fixed time intervals.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

False is the correct answer to “The designation rms means repetitions measured per second.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

100 Hz is the correct answer to “A saw-tooth wave has a period of 10 ms. Its frequency is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

0 V is the correct answer to “The average value of a 12 V peak sine wave over one complete cycle is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

False is the correct answer to “The duty cycle of a pulse waveform with a pulse width of 10 µs and a period of 100 µs is 25%.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

1.5 mA is the correct answer to “If the rms voltage drop across a 15 kΩ resistor is 16 V, the peak current through the resistor is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

True is the correct answer to “The angular position of a phasor represents the angle of the sine wave with respect to a reference.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

True is the correct answer to “The unit of frequency is the hertz.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

60° is the correct answer to “How many degrees are there in p/3 rad”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

54.4 V is the correct answer to “If the rms current through a 6.8 kΩ resistor is 8 mA, the rms voltage drop across the resistor is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

26.6 V is the correct answer to “If the rms current through a 4.7 kΩ resistor is 4 mA, the peak voltage drop across the resistor is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

25% is the correct answer to “A pulse waveform has a high time of 8 ms and a pulse width of 32 ms. The duty cycle is”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

True is the correct answer to “The length of a phasor represents the amplitude.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

40° is the correct answer to “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”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

False is the correct answer to “Duty cycle is the characteristic of a pulse waveform that indicates the high time versus the low time.”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.

Is 30% is the correct answer to “A 20 kHz pulse waveform consists of pulses that are 15 µs wide. The duty cycle”. This question is standard in competitive examination syllabi for Alternating Current And Voltage.