Engineering
Engineering MCQs With Answers
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A Megger is a special type of instrument designed specifically to measure:
ALow armature resistance
BHigh insulation resistance
CLine frequency
DAC power factor
Salient-pole rotors are preferred in alternators driven by:
AHigh-speed gas turbines
BHigh-speed steam turbines
CLow-speed hydro turbines
DNuclear reactors
In a 3-phase star-connected balance system, the line voltage V_L is related to phase voltage V_ph by:
AV_L = 3 * V_ph
BV_L = V_ph
CV_L = V_ph / sqrt(3)
DV_L = sqrt(3) * V_ph
In an alternator, using short-pitched coils primarily helps to:
AIncrease leakage reactance
BIncrease total generated voltage
CReduce mechanical friction
DEliminate specific high-frequency harmonics from induced voltage
What type of rotor is used in steam-turbine driven alternators (turbo-generators) running at high speeds (3000 RPM)?
AWound slip-ring rotor
BSalient pole rotor
CSmooth cylindrical rotor
DSquirrel cage rotor
According to the Nyquist-Shannon sampling theorem, to prevent aliasing, the minimum sampling rate f_s must be:
AAt least twice the maximum message frequency (2 * f_max)
BHalf of the maximum message frequency (0.5 * f_max)
CEqual to the maximum message frequency (f_max)
DFour times the maximum message frequency (4 * f_max)
Pitch factor (or chord factor) K_p of an alternator coil short-pitched by angle alpha is equal to:
Asin(alpha / 2)
Bcos(alpha / 2)
Ctan(alpha / 2)
Dcos(alpha)
A two-port linear network is classified as reciprocal if its Z-parameters satisfy which condition?
AZ11 = Z22
BZ11 * Z22 = Z12 * Z21
CZ12 = -Z21
DZ12 = Z21
A two-port linear network is defined as symmetrical if its ABCD transmission parameters satisfy:
AAD - BC = 1
BA = D
CB = C
DA = B
In a Boost converter (step-up DC-DC chopper), the average output voltage V_o is given by:
AV_o = D * V_s
BV_o = D * V_s / (1 - D)
CV_o = V_s / (1 - D)
DV_o = (1 - D) * V_s