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 18 of 30
- A. 10 V
- B. 10.3 V
- C. 10.7 V
- D. 9.3 V
Explanation: Since we have the voltage at AC input, which is 10 V, we just need to subtract this value by the diode drop, which is 0.7 V;10 - 0.7 = 9.3V
Correct answer: 9.3 V- A. Vm
- B. Vm/√2
- C. 2Vm
- D. Vm3
Explanation: A full-wave rectifier is defined as a rectifier that converts the complete cycle of alternating current into pulsating direct current…
Correct answer: 2Vm- A. Forward
- B. Reverse
- C. Mid
- D. Positive
Explanation: Correct option is A. A diode works in forward bias for rectification. Rectification is the process of converting alternating current (AC)…
Correct answer: Forward344. In a step-down transformer, the current in the primary coil is _ than that in the secondary coil.
- A. None of these
- B. More
- C. Equal
- D. Less
Explanation: In a step-down transformer, the voltage in the primary coil is higher than in the secondary coil; the final voltage is reduced.
Correct answer: Less- A. Transformer
- B. None of these
- C. Inductor
- D. Capacitor
Explanation: This option is correct. An AC generator is similar to an inductor in that both use magnetic fields to store and transfer energy.
Correct answer: Inductor- A. Equal to
- B. Greater than
- C. Less than
- D. None of these
Explanation: For an ideal step-up transformer, Ps is equal to Pp as there are no power losses.
Correct answer: Equal to- A. 4.4 sin(314t) Ma
- B. 4.4 sin(l 57t) mA
- C. 6.2 sin(314t) mA
- D. 6.2 sin(l 57t) mA
Explanation: Following is the explanation to this question:
Correct answer: 6.2 sin(314t) mA- A. Zero
- B. 1
- C. More than 1
- D. Infinite
Explanation: If the coefficient of coupling has value one, then it is called as the perfect coupling that is when the entire flux of one coil links the…
Correct answer: 1- A. 358.98mW
- B. 275.2mW
- C. 45.16 mW
- D. 456.78 Mw
Explanation: The AC power input =IRMS2(RF+Rr).IRMS=Im/√2=Vm/(Rf+RL)√2=30/(1500+10)*1.414=13.5mASo, AC power INPUT=(13.5*10-3)2*(1500+10)=275.2mW
Correct answer: 275.2mW- A. N
- B. N3
- C. N2
- D. 1/N
Explanation: Self-inductance is defined as the property of a coil by which a changing current through it induces an electromotive force (EMF) in the…
Correct answer: N2- A. 0.5 x 10^-3 second
- B. 0.5 second
- C. 5 second
- D. 2 second
Explanation: Frequency is the reciprocal of a time period.The frequency given as 2 kHz is equal to: f = 2kHz = 2 × 10³ HzHence, T = 1/f T = 1/ 2 × 10³…
Correct answer: 0.5 x 10^-3 second- A. Half wave
- B. Full wave
- C. Bridge
- D. All of the above options are correct
Explanation: Bridge rectifier uses wheatstone bridge to rectify signal: Four diodes are used Two diodes remains on (Forward Biased) in each hafe of the…
Correct answer: Bridge- A. 9 V
- B. 18 V
- C. 4.5 V
- D. 0 V
Explanation: Peak to peak voltage is the double of peak voltage
Correct answer: 18 V- A. 2V
- B. 10V
- C. 4V
- D. 5V
Explanation: Value of AC from peak to next peak is 2Vo . So , here 5 V is the peak voltage.
Correct answer: 5V- A. Period
- B. Cycle
- C. Instantaneous value
- D. Sine wave
Explanation: The time duration required to complete one complete cycle is known as the period.
Correct answer: Period- A. From a source which is not the same as the unknown voltage
- B. From a battery
- C. From the same source as the unknown voltage
- D. Any of the above options are correct
Explanation: It is desirable to take the supply for the potentiometer from the same source as the unknown voltage in order to measure the AC voltage.
Correct answer: From the same source as the unknown voltage- A. AC voltage
- B. High AC voltage
- C. DC voltage
- D. Low AC voltage
Explanation: AC generator is a mechanical device that converts mechanical energy into AC electrical power.
Correct answer: DC voltage- A. Transformers
- B. Inductors
- C. Capacitors
- D. Motor
Explanation: Converting energy from one form to another is the key to understanding the differences between electric motors and generators.
Correct answer: Motor- A. Amplification
- B. Rectification
- C. Modulation
- D. Both B & C
Explanation: A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC).
Correct answer: Rectification- A. Io
- B. √2Io
- C. Io/√2
- D. 2Io
Explanation: The explanation for this question has been added!
Correct answer: Io/√2