Free Alternating Current MCQs with Answers
592 Alternating Current MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
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Read the Alternating Current notesFree MDCAT chapter notes with key terms592 questions · page 12 of 30
- A. ohm
- B. Volt-m
- C. Ampere
- D. Volt
Explanation: The correct option, ohm (Ω), represents the SI unit of reactance. Reactance, whether capacitive or inductive, is measured in ohms, which…
Correct answer: ohm- A. r.m.s. value
- B. Peak value
- C. Average value
- D. None of the above
Explanation: The correct option, r.m.s. value, represents the root mean square value of alternating current or electromotive force.
Correct answer: r.m.s. value- A. Io
- B. 1/2
- C. I
- D. None of the above
Explanation: The correct option, "None of the above," indicates that none of the provided options accurately represents the average value of an…
Correct answer: None of the above- A. Frequency
- B. Time period
- C. Amplitude
- D. Cycle
Explanation: The correct option, "cycle," refers to one complete set of positive and negative values of an alternating quantity.
Correct answer: Cycle- A. 1/ωL
- B. ωL
- C. ω2L2
- D. ωLR
Explanation: The correct option, ωL, represents the inductive reactance in an AC circuit, where ω is the angular frequency and L is the inductance of…
Correct answer: ωL- A. Varies inversely with time
- B. Varies directly with time
- C. Independent of time
- D. Varies sinusoidally with time
Explanation: The correct option, "Varies sinusoidally with time," describes alternating voltage in AC circuits accurately, indicating that voltage…
Correct answer: Varies sinusoidally with time- A. Very low cost
- B. To very high cost
- C. long distance
- D. both a and c
Explanation: The correct option, "both a and c," indicates that alternating current (AC) can be transmitted over long distances (option c) and, in some…
Correct answer: both a and c- A. Keeps on reversing with time
- B. Remains the same
- C. Reverses after period
- D. None of these
Explanation: The correct option is that in alternating current (AC), the voltage source polarity keeps on reversing with time, leading to a continuous…
Correct answer: Keeps on reversing with time- A. π
- B. Zero
- C. π/2
- D. 2π
Explanation: Explanation is provided in the picture below.
Correct answer: π- A. -Vo
- B. Vo
- C. Vo=0
- D. None of these
Explanation: Explanation is provided in picture below.
Correct answer: -Vo- A. Current and time
- B. Voltage and time
- C. Voltage and current
- D. Voltage along y-axis and time along x-axis
Explanation: "Voltage along y-axis and time along x-axis," represents the waveform of alternating voltage.
Correct answer: Voltage along y-axis and time along x-axis- A. Square
- B. Sinusoidal
- C. Rectangular
- D. None of these
Explanation: The correct option is "Sinusoidal." This means that the waveform of alternating voltage follows a smooth, periodic pattern resembling a…
Correct answer: Sinusoidal- A. 2VO
- B. Vo
- C. Vo/2
- D. None of these
Explanation: The correct option is (Vo)), representing twice the peak voltage (Vo). It signifies the full extent of voltage variation between the…
Correct answer: 2VO- A. Zero
- B. 0.7Vmax
- C. 0.707Vmax
- D. None of these
Explanation: The correct option is "zero." For a sinusoidal waveform, which is common in AC circuits, the average value of alternating voltage over a…
Correct answer: Zero- A. 0.5 times the peak value
- B. 0.7 times the peak value
- C. 0.7 times the instantaneous value
- D. Equal to maximum voltage
Explanation: The correct option is "0.7 times the peak value." This means that the RMS (Root Mean Square) value of alternating voltage is approximately…
Correct answer: 0.7 times the peak value- A. Its RMS value
- B. Square root of its mean square value
- C. Peak value
- D. Instantaneous value
Explanation: The correct option is "its RMS value." The RMS (Root Mean Square) value represents the effective or equivalent value of the alternating…
Correct answer: Its RMS value- A. Always decreases
- B. Always increases
- C. Always remains the same
- D. Does not remain the same
Explanation: The correct option, "Does Not Remain the Same," indicates that the magnitude of alternating voltage changes over time, fluctuating between…
Correct answer: Does not remain the same- A. An inductor
- B. A resistor
- C. A capacitor
- D. None of these
Explanation: The correct option is a resistor. In a DC circuit, resistors are the basic circuit elements that regulate current flow and voltage levels…
Correct answer: A resistor- A. Thermistor
- B. Inductor and resistors
- C. Inductor and capacitor
- D. All of above
Explanation: The correct option is "inductor and capacitor." In AC circuits, inductors and capacitors are the basic circuit elements due to their…
Correct answer: Inductor and capacitor- A. Io=RxVo
- B. Io=Vo/R
- C. Io=R/Vo
- D. Io=Vo x R
Explanation: The correct option, "Io = Vo/R," follows Ohm's law for AC circuits, stating that the maximum current (Io) through a resistor (R) connected…
Correct answer: Io=Vo/R