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 →
In a 3-phase induction motor, maximum torque is independent of:
AStator supply voltage
BStator leakage reactance
CRotor resistance at standstill
DSynchronous speed
Eddy current loss in a transformer core is directly proportional to:
AInverse of thickness (1/t)
BSquare of frequency (f^2) and square of core thickness (t^2)
CFrequency (f) only
DSquare root of frequency
Open-circuit test on a transformer is conducted at rated voltage to determine:
AWinding resistance
BFull-load copper losses
CStray load loss
DCore losses (iron losses) and magnetizing branch parameters
The crest factor (peak factor) of a pure sinusoidal waveform is:
A1.414
B2.0
C1.11
D0.707
The energy stored in a magnetic field of an inductor L carrying current I is given by:
A0.5 * L^2 * I
BL * I^2
C0.5 * L * I^2
DL / I
In a parallel resonant LC circuit, the impedance at resonance frequency is:
AMaximum (theoretically infinite)
BMinimum (zero)
CEqual to capacitive reactance
DEqual to inductive reactance
The reciprocity theorem is applicable to networks that are:
AUnilateral and linear
BLinear, bilateral, and passive
CNon-linear and active
DParametric and non-linear
The maximum power transfer theorem states that maximum power is delivered to the load when load resistance equals:
AZero ohms
BThevenin equivalent resistance of the source circuit
CHalf of Thevenin equivalent resistance
DDouble the Thevenin equivalent resistance
In an R-L series circuit connected to an AC source, the phase angle theta by which current lags voltage is given by:
Aarccos(R / (omega * L))
Barctan(omega * L / R)
Carcsin(omega * L / R)
Darctan(R / (omega * L))
Double Sideband Suppressed Carrier (DSB-SC) modulation requires what percentage saving in total transmitted power compared to standard AM (m=1)?
A100%
B33.3%
C50.0%
D66.7%