Principles and Practice of Electrical and
Computer Engineering Examination Questions
With Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. In a balanced three-phase system, the primary advantage of using
three-phase power rather than single-phase power is:
A. Lower frequency
B. Reduced insulation requirements
C. More constant power delivery and efficient transmission
D. Elimination of reactive power
Rationale: Three-phase systems provide nearly constant power
transfer to loads, reducing vibration in motors and improving
transmission efficiency. They also require less conductor material for
the same amount of transmitted power compared with equivalent
single-phase systems.
2. Ohm's Law states that current is equal to:
A. Voltage multiplied by resistance
B. Voltage divided by resistance
, C. Resistance divided by voltage
D. Power divided by voltage
Rationale: Ohm's Law is expressed as I = V/R, where current (I) is
directly proportional to voltage (V) and inversely proportional to
resistance (R). It is one of the most fundamental relationships in
electrical engineering.
3. A transformer operates on the principle of:
A. Electrostatic induction
B. Thermoelectric effect
C. Electromagnetic induction
D. Piezoelectricity
Rationale: Transformers transfer energy between windings through
mutual electromagnetic induction. A changing magnetic field
produced by the primary winding induces voltage in the secondary
winding.
4. Which semiconductor device is commonly used as a controlled
rectifier?
A. Diode
B. MOSFET
C. BJT
D. SCR
,Rationale: A Silicon Controlled Rectifier (SCR) allows controlled
conduction after gate triggering and is widely used in power-control
applications such as motor drives and controlled rectification.
5. The SI unit of capacitance is:
A. Henry
B. Ohm
C. Volt
D. Farad
Rationale: Capacitance measures a component's ability to store
electrical charge. The standard SI unit is the farad (F), defined as one
coulomb per volt.
6. In digital systems, a flip-flop is primarily used for:
A. Amplification
B. Frequency modulation
C. Data storage
D. Power conversion
Rationale: Flip-flops are bistable devices capable of storing one bit of
information. They form the basis of registers, counters, and memory
elements in digital electronics.
7. The power factor of a purely resistive circuit is:
A. 0
, B. 0.5
C. 0.707
D. 1.0
Rationale: In a purely resistive circuit, voltage and current are in
phase, resulting in a phase angle of zero degrees. Therefore, power
factor equals cos(0°) = 1.
8. Kirchhoff's Current Law is based on conservation of:
A. Energy
B. Momentum
C. Charge
D. Power
Rationale: KCL states that the algebraic sum of currents entering and
leaving a node equals zero. This principle derives directly from
conservation of electric charge.
9. Which logic gate produces a HIGH output only when all inputs are
HIGH?
A. OR
B. XOR
C. NAND
D. AND
Computer Engineering Examination Questions
With Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. In a balanced three-phase system, the primary advantage of using
three-phase power rather than single-phase power is:
A. Lower frequency
B. Reduced insulation requirements
C. More constant power delivery and efficient transmission
D. Elimination of reactive power
Rationale: Three-phase systems provide nearly constant power
transfer to loads, reducing vibration in motors and improving
transmission efficiency. They also require less conductor material for
the same amount of transmitted power compared with equivalent
single-phase systems.
2. Ohm's Law states that current is equal to:
A. Voltage multiplied by resistance
B. Voltage divided by resistance
, C. Resistance divided by voltage
D. Power divided by voltage
Rationale: Ohm's Law is expressed as I = V/R, where current (I) is
directly proportional to voltage (V) and inversely proportional to
resistance (R). It is one of the most fundamental relationships in
electrical engineering.
3. A transformer operates on the principle of:
A. Electrostatic induction
B. Thermoelectric effect
C. Electromagnetic induction
D. Piezoelectricity
Rationale: Transformers transfer energy between windings through
mutual electromagnetic induction. A changing magnetic field
produced by the primary winding induces voltage in the secondary
winding.
4. Which semiconductor device is commonly used as a controlled
rectifier?
A. Diode
B. MOSFET
C. BJT
D. SCR
,Rationale: A Silicon Controlled Rectifier (SCR) allows controlled
conduction after gate triggering and is widely used in power-control
applications such as motor drives and controlled rectification.
5. The SI unit of capacitance is:
A. Henry
B. Ohm
C. Volt
D. Farad
Rationale: Capacitance measures a component's ability to store
electrical charge. The standard SI unit is the farad (F), defined as one
coulomb per volt.
6. In digital systems, a flip-flop is primarily used for:
A. Amplification
B. Frequency modulation
C. Data storage
D. Power conversion
Rationale: Flip-flops are bistable devices capable of storing one bit of
information. They form the basis of registers, counters, and memory
elements in digital electronics.
7. The power factor of a purely resistive circuit is:
A. 0
, B. 0.5
C. 0.707
D. 1.0
Rationale: In a purely resistive circuit, voltage and current are in
phase, resulting in a phase angle of zero degrees. Therefore, power
factor equals cos(0°) = 1.
8. Kirchhoff's Current Law is based on conservation of:
A. Energy
B. Momentum
C. Charge
D. Power
Rationale: KCL states that the algebraic sum of currents entering and
leaving a node equals zero. This principle derives directly from
conservation of electric charge.
9. Which logic gate produces a HIGH output only when all inputs are
HIGH?
A. OR
B. XOR
C. NAND
D. AND
