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 98 of 158
- A. negative gate voltage only
- B. positive gate voltage only
- C. positive as well as negative gate voltage
- D. none of the above
Explanation: MOSFET operation depends on its channel type: an n-channel device uses positive gate bias relative to the source, while a p-channel device…
Correct answer: positive as well as negative gate voltage- A. electrons
- B. holes
- C. both electrons and holes
- D. none of the above
Explanation: A p-channel JFET conducts through a p-type channel, where holes are the majority charge carriers.
Correct answer: holes- A. reverse
- B. forward
- C. reverse as well as forward
- D. none of the above
Explanation: The JFET gate-channel junction is normally reverse biased, so its gate current is nearly zero and its input resistance is very high.
Correct answer: reverse- A. cathode, anode, grid
- B. emitter, base, collector
- C. source, gate, drain
- D. none of the above
Explanation: The three terminals of a JFET are the source, gate, and drain. Emitter, base, and collector belong to a BJT, while anode, cathode, and…
Correct answer: source, gate, drain- A. decreases
- B. increases
- C. remains constant
- D. none of the above
Explanation: At pinch-off, the JFET enters its saturation or constant-current region, where further increases in drain voltage produce nearly no…
Correct answer: remains constant- A. unipolar
- B. bipolar
- C. unijunction
- D. none of the above
Explanation: A JFET is called unipolar because conduction is produced by only one type of majority carrier, either electrons or holes.
Correct answer: unipolar- A. equal to
- B. less than
- C. more than
- D. none of the above
Explanation: Because the reverse-biased JFET gate junction draws almost no current, its input impedance is much higher than that of an ordinary BJT.
Correct answer: more than- A. Receiving antenna
- B. Radio transmitter
- C. Radio receiver
- D. Television receiver
Explanation: A clamping circuit shifts the entire waveform upward or downward without substantially changing its shape, a function commonly used in…
Correct answer: Television receiver- A. ICBO
- B. ICEO
- C. (ß + 1) ICEO
- D. IC(sat)
Explanation: In CE cutoff, the base is open in the leakage-current model, so the collector current is the collector-to-emitter leakage current, ICEO.
Correct answer: ICEO- A. Off
- B. Saturation
- C. Active
- D. None of the above
Explanation: For amplification, the transistor must remain in the active region, where collector current varies approximately with base current and the…
Correct answer: Active- A. Negative
- B. Positive
- C. Both positive and negative
- D. None of the above
Explanation: A negative clipper is designed to remove or limit the negative half-cycles of an input waveform while allowing the positive half-cycles to…
Correct answer: Negative- A. Negative
- B. 100 % positive
- C. Both positive and negative
- D. None of the above
Explanation: A multivibrator uses regenerative, or positive, feedback so that a small change is reinforced and the circuit rapidly switches between…
Correct answer: 100 % positive- A. Two stable states
- B. One stable state
- C. No stable state
- D. None of the above
Explanation: A bistable multivibrator has two stable states and remains in either state until an external trigger changes it.
Correct answer: Two stable states- A. 5 times greater than
- B. 5 times smaller than
- C. Equal to
- D. At least 10 times greater than
Explanation: An RC integrator requires the capacitor voltage to change slowly compared with the input waveform, so the time constant must be much…
Correct answer: At least 10 times greater than- A. No stable state
- B. One stable state
- C. Two stable states
- D. None of the above
Explanation: A monostable multivibrator has one stable state and one temporary state.
Correct answer: One stable state- A. Negative
- B. Positive
- C. Both positive and negative
- D. None of the above
Explanation: A positive clipper removes or limits the positive half-cycles while allowing the negative half-cycles to pass.
Correct answer: Positive- A. Monostable
- B. Bistable
- C. Astable
- D. None of the above
Explanation: An astable multivibrator has no stable state and continuously switches between its two quasi-stable states.
Correct answer: Astable- A. VCC
- B. 0
- C. VCC/2
- D. VCC/3
Explanation: In the usual common-emitter transistor switch, cutoff makes collector current essentially zero, so there is no voltage drop across the…
Correct answer: VCC1959. If d.c. supply of 10 V is fed to a differentiating circuit, then output will be_______________?
- A. 20 V
- B. 10 V
- C. 0 V
- D. None of the above
Explanation: A differentiator responds to changes in voltage, and a steady DC level has zero rate of change after the switching transient.
Correct answer: 0 V- A. Sine wave
- B. Sharp narrow pulses
- C. Rectangular wave
- D. Triangular wave
Explanation: A differentiator produces a large pulse whenever the input changes rapidly.
Correct answer: Sharp narrow pulses