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 104 of 158
- A. decreasing its temperature
- B. increasing its temperature
- C. decreasing its vibration
- D. increasing its vibration
Explanation: In metallic conductors, lowering temperature reduces lattice vibrations and electron scattering, thereby increasing conductivity.
Correct answer: decreasing its temperature- A. generating very strong magnetic field
- B. manufacture of bubble memories
- C. generating electrostatic field
- D. generating regions free from magnetic field
Explanation: A superconductor can carry very large current with negligible resistance, producing extremely strong magnetic fields in devices such as…
Correct answer: generating very strong magnetic field- A. highest conductivity
- B. lowest temperature co-efficient
- C. good mechanical strength
- D. good corrosion resistance
- E. easy solderable and drawable quality
- F. all of the above
Explanation: A practical highly conductive material should combine high conductivity with a low temperature coefficient, mechanical strength, corrosion…
Correct answer: all of the above- A. 2
- B. 4
- C. 6
- D. 8
Explanation: In a simple cubic lattice, each atom has four neighbours in its own plane plus one along each of the three-dimensional opposite…
Correct answer: 6- A. less than that of unbounded electron
- B. greater than that of unbounded electron
- C. equal to that of unbounded electron
- D. infinite
- E. none of the above
Explanation: A bound electron is confined to an atom and has less available energy than a free or unbound electron in the elementary energy-band…
Correct answer: less than that of unbounded electron- A. copper
- B. aluminium
- C. both (A) and (B)
- D. copper and silver
- E. platinum and gold
Explanation: Copper and aluminium are the most commonly used conducting materials because they combine good conductivity with practical cost and…
Correct answer: both (A) and (B)- A. zero conductivity
- B. unity conductivity
- C. infinite conductivity
- D. none of the above
Explanation: A perfect conductor has zero resistance, and since conductivity is the reciprocal of resistivity, its conductivity is treated as infinite.
Correct answer: infinite conductivity2068. The formula __________ determines the number of electrons that can be accommodated in any level?
- A. 2n2
- B. 4n2
- C. 2n3
- D. 4ns
Explanation: The maximum number of electrons in the nth principal energy level is given by 2n².
Correct answer: 2n2- A. malleability
- B. toughness
- C. softness
- D. none of the above
Explanation: Hardness is resistance to scratching, indentation or deformation, so its converse is softness.
Correct answer: softness- A. Proton
- B. Neutron
- C. Electron
- D. None of the above
Explanation: An electron carries a negative electric charge and moves around the positively charged nucleus.
Correct answer: Electron- A. unit cell
- B. space lattice
- C. either A. or (b)
- D. none of the above
Explanation: A unit cell is the smallest repeating block of atoms whose repetition builds the crystal structure.
Correct answer: unit cell- A. transfer of electrons between atoms
- B. sharing of electrons between atoms
- C. sharing of variable number of electrons by a variable number of atoms
- D. none of the above
Explanation: A covalent bond forms when atoms share one or more pairs of valence electrons. Transfer of electrons is characteristic of an ionic bond.
Correct answer: sharing of electrons between atoms- A. Less than 5
- B. Less than 10
- C. More than 10
- D. None of the above
Explanation: A tuned amplifier is designed to respond strongly around one narrow resonant frequency, so its quality factor is normally high, commonly…
Correct answer: More than 10- A. IF
- B. Audio
- C. Output
- D. None of the above
Explanation: Double-tuned circuits provide good selectivity together with the required bandwidth in the intermediate-frequency section of a radio…
Correct answer: IF- A. Loose
- B. Tight
- C. Critical
- D. None of the above
Explanation: Loose coupling gives a narrower resonance curve and therefore better selectivity.
Correct answer: Loose- A. Sensitivity
- B. Fidelity
- C. Selectivity
- D. None of the above
Explanation: The Q-factor of a tuned circuit indicates how sharply it responds around resonance.
Correct answer: Selectivity- A. 10kHz
- B. 40 kHz
- C. 30 kHz
- D. 20 kHz
Explanation: For a tuned circuit, Q = fr/BW, so BW = fr/Q = 1000 kHz/50 = 20 kHz. The resonant frequency and Q directly determine the bandwidth.
Correct answer: 20 kHz- A. A pure resistive
- B. A pure inductive
- C. A pure capacitive
- D. A resonant tank
Explanation: A class C transistor conducts for less than half a cycle, so its pulsed output must be shaped by a tuned resonant circuit.
Correct answer: A resonant tank- A. Resistive
- B. Capacitive
- C. LC tank
- D. Inductive
Explanation: A tuned amplifier uses a resonant LC tank as its load, giving high impedance and maximum voltage gain near the selected resonant…
Correct answer: LC tank- A. Radio frequency
- B. Low frequency
- C. Audio frequency
- D. None of the above
Explanation: Tuned amplifiers are designed to select and amplify a narrow band of frequencies, which is especially useful in radio-frequency receivers…
Correct answer: Radio frequency