Q.1
The ferrite cores are used for ____________ transformers.
  • a) Small transformers
  • b) Medium transformers
  • c) Large transformers
  • d) Medium and small transformers
Q.2
A 2-pole, 3-phase,Hz induction motor is operating at a speed ofrpm. The frequency of the rotor current of the motor in Hz is __________
  • a) 43.33
  • b) 42.54
  • c) 43.11
  • d) 41.47
Q.3
Calculate the phase angle of the sinusoidal waveform w(t)=.45sin(87πt+8π÷787).
  • a) 2π÷39
  • b) 8π÷787
  • c) 5π÷74
  • d) 42π÷4
Q.4
Calculate the moment of inertia of the disc having a mass of 1 kg and radius of 1 m.
  • a) 1 kgm2
  • b) .5 kgm2
  • c) 2 kgm2
  • d) 3 kgm2
Q.5
Calculate the moment of inertia of the thin spherical shell having a mass of 3 kg and diameter of 6 cm.
  • a) .0178 kgm2
  • b) .0147 kgm2
  • c) .0398 kgm2
  • d) .0144 kgm2
Q.6
The power factor of a synchronous motor __________
  • a) Improves with an increase in excitation and may even become leading at high excitations
  • b) Decreases with increase in excitation
  • c) Is independent of its excitation
  • d) Increase with loading for a given excitation
Q.7
The frame of a synchronous motor is made of _________
  • a) Aluminum
  • b) Silicon steel
  • c) Cast iron
  • d) Stainless steel
Q.8
The slope of the V-I curve is 45°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.
  • a) 2 Ω
  • b) 3 Ω
  • c) 4 Ω
  • d) 1 Ω
Q.9
Which one of the following methods would give a higher than the actual value of regulation of the alternator.
  • a) ZPF method
  • b) MMF method
  • c) EMF method
  • d) ASA method
Q.10
A 3-phase induction motor runs at almostrpm at no load andrpm at full load when supplied with power from aHz, 3-phase supply. What is the corresponding speed of the rotor field with respect to the rotor?
  • a) 430 revolution per minute
  • b) 440 revolution per minute
  • c) 460 revolution per minute
  • d) 450 revolution per minute
Q.11
Which of the following core has linear characteristics?
  • a) Air core
  • b) Steel core
  • c) CRGO core
  • d) Iron core
Q.12
Calculate the active power in a 1 Ω resistor with 2 A current flowing through it.
  • a) 2 W
  • b) 4 W
  • c) 7 W
  • d) 1 W
Q.13
The slope of the V-I curve is 13°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.
  • a) .2544 Ω
  • b) .7771 Ω
  • c) .2308 Ω
  • d) .5788 Ω
Q.14
A 2-pole lap wound generator witharmature conductors and a flux per pole of .Wb has an armature current ofA. The developed torque is _________
  • a) 39.7 N-m
  • b) 39.2 N-m
  • c) 38.4 N-m
  • d) 37.2 N-m
0 h : 0 m : 1 s