All Free Electrical Engineering MCQs with Answers
Every Electrical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
3,143 questions · page 3 of 158
- A. 12 V
- B. 24 V
- C. 0 V
- D. 6 V
Explanation: Equal resistors in a voltage divider split the source voltage equally. Thus the output is 24/2 = 12 V, assuming the output is taken across…
Correct answer: 12 V- A. Both R and C
- B. R
- C. C
- D. None of the above
Explanation: For an RC integrator, the output is taken across the capacitor because capacitor voltage is proportional to the time integral of current.
Correct answer: C- A. R
- B. C
- C. Both R and C
- D. None of the above
Explanation: For an RC differentiator, the output is taken across the resistor because resistor voltage follows current, while the capacitor current is…
Correct answer: R- A. electrons only
- B. positive ions only
- C. negative ions only
- D. positive and negative ions
- E. none of the above
Explanation: In metallic conductors, current is produced by the drift of free electrons; the positive metal ions remain bound in the crystal lattice.
Correct answer: electrons only- A. non-linear conductor
- B. reverse conductor
- C. bad-conductor
- D. non-conductor
Explanation: A conductor whose voltage-current relationship is not proportional does not obey Ohm's law and is called a non-linear conductor.
Correct answer: non-linear conductor- A. Resistive
- B. Capacitive
- C. Inductive
- D. None of the above
Explanation: Below resonance, the inductive reactance is smaller than the capacitive reactance in a series LC circuit, so the net reactance is…
Correct answer: Capacitive- A. Both voltage and current amplification
- B. Voltage amplifications
- C. Current amplification
- D. None of the above
Explanation: At parallel resonance, the inductor and capacitor exchange large circulating currents while the supply current is comparatively small.
Correct answer: Current amplification48. For frequencies above the resonant frequency, a parallel LC circuit behaves as a ____________ load?
- A. Capacitive
- B. Resistive
- C. Inductive
- D. None of the above
Explanation: Above parallel resonance, capacitive susceptance exceeds inductive susceptance, making the total admittance capacitive and the equivalent…
Correct answer: Capacitive- A. Voltage amplification
- B. Current amplification
- C. Both voltage and current amplification
- D. None of the above
Explanation: At series resonance, the impedance is minimum and current is maximum, while the voltage across the inductor or capacitor can be many times…
Correct answer: Voltage amplification- A. XL decreases and XC increases
- B. XL increases and XC decreases
- C. Line current becomes minimum
- D. None of the above
Explanation: When frequency falls, inductive reactance XL = 2πfL decreases, while capacitive reactance XC = 1/(2πfC) increases.
Correct answer: XL decreases and XC increases51. For frequencies above the resonant frequency , a series LC circuit behaves as a ____________load?
- A. Resistive
- B. Inductive
- C. Capacitive
- D. None of the above
Explanation: Above resonance, XL is greater than XC, so the net reactance is positive.
Correct answer: Inductive- A. Inductive
- B. Resistive
- C. Capacitive
- D. None of the above
Explanation: Below resonance, the parallel circuit's net susceptance is capacitive, but its impedance has negative reactance and therefore appears…
Correct answer: Inductive- A. 90o
- B. 180o
- C. 0o
- D. None of the above
Explanation: At parallel resonance, the inductive and capacitive reactive currents cancel, leaving the supply current in phase with the applied…
Correct answer: 0o- A. Very large
- B. Zero
- C. Small
- D. None of the above
Explanation: A practical parallel tuned circuit is designed with a large L/C ratio because its quality factor varies with the square root of L/C.
Correct answer: Very large- A. Is decreased
- B. Is increased
- C. Remains the same
- D. None of the above
Explanation: For the practical parallel resonant circuit represented here, Q is proportional to √(L/C) when the effective resistance is fixed.
Correct answer: Is increased- A. Zero
- B. Inductive
- C. Capacitive
- D. None of the above
Explanation: At series resonance, inductive and capacitive reactances are equal and opposite, so their reactive effects cancel.
Correct answer: Zero- A. 0
- B. 5
- C. 1
- D. 8
Explanation: Resonance cancels the net reactance, leaving the circuit impedance effectively resistive.
Correct answer: 1- A. Capacitive
- B. Resistive
- C. Inductive
- D. None of the above
Explanation: Although inductors and capacitors are present, their susceptances or reactances cancel at resonance.
Correct answer: Resistive- A. Is increased
- B. Is decreased
- C. Remains the same
- D. None of the above
Explanation: For a tuned circuit, Q is inversely proportional to its effective resistance, such as Q = ωL/R for a series-resonant circuit.
Correct answer: Is decreased- A. 90o
- B. 180o
- C. 0o
- D. None of the above
Explanation: At series resonance, the circuit impedance is purely resistive, so the applied voltage and circuit current are in phase.
Correct answer: 0o