Electrical Engineering
Electrical Engineering MCQs with Answers
Electrical engineering MCQs with answers and detailed explanations for PEC, NTS, WAPDA and engineering job tests. Machines, circuits and power systems. Take a scored quiz instead →
The surge impedance of a typical overhead transmission line is in the range of:
A1 to 10 ohms
B4000 to 5000 ohms
C40 to 50 ohms
D400 to 500 ohms
Diversity factor of a power generation system is defined as the ratio of:
AMaximum demand to connected load
BInstalled capacity to peak demand
CSum of individual maximum demands to simultaneous maximum demand of system
DAverage demand to peak demand
Negative sequence components of current are present during:
ASymmetrical 3-phase short circuit faults
BBalanced normal operation only
CZero current open circuit
DUnbalanced faults and unbalanced loads
Corona loss in overhead transmission lines decreases with an increase in:
ASystem voltage
BAir density factor reduction
CSupply frequency
DConductor radius and spacing between conductors
Proximity effect in transmission lines causes:
AUniform distribution of current density
BComplete loss of line capacitance
CNon-uniform distribution of current density across the conductor cross-section
DReduction of conductor temperature
Buchholz relay is a gas-actuated relay used for protecting:
ASynchronous generators against overspeed
BDistribution feeder cables
CHigh voltage transmission lines
DOil-immersed transformers against internal fault
Dummy coils are used in DC armatures with wave winding to:
AEliminate commutation spark
BIncrease generated emf
CMaintain mechanical balance of the armature rotor
DReduce armature reaction
The function of a conservator tank in an oil-immersed transformer is to:
ATake up expansion and contraction of transformer oil due to temperature changes
BCool the transformer windings directly
CPrevent overvoltage surges
DFilter out moisture from incoming air
In a DC series motor, if the field winding gets open-circuited while running under no load, the motor will:
AReverse direction of rotation
BStop immediately
CAttain dangerously high speed
DRun at normal rated speed
The inverted V-curve of a synchronous motor plots power factor against:
AField current (Excitation)
BLoad torque
CRotor speed
DArmature current