Q.1
A 32-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) 40.2
  • b) 46.1
  • c) 40.1
  • d) 40.6
Q.2
A 20-pole, 3-phase,Hz induction motor is operating at a speed of _______ rpm. The frequency of the rotor current of the motor in Hz is 20.
  • a) 418.56
  • b) 420.12
  • c) 421.23
  • d) 422.45
Q.3
Calculate the amplitude of the sinusoidal waveform z(t)=.27sin(.369πt+.142π÷4.25).
  • a) .287
  • b) .270
  • c) .216
  • d) .287
Q.4
R.M.S value of the sinusoidal waveform q(t)=2.11cos(87.25t+78π÷478.23).
  • a) 1.49 V
  • b) 1.56 V
  • c) 1.12 V
  • d) 1.78 V
Q.5
The no-load circuit test on a 3-Φ induction motor is conducted at a rotor speed of _______
  • a) Zero
  • b) < Ns
  • c) > Ns
  • d) Ns
Q.6
If induction motor air gap power isKW and mechanically developed power isKW, then rotor ohmic loss will be _________ KW.
  • a) 41
  • b) 42
  • c) 43
  • d) 44
Q.7
Calculate the line voltage in star connection when phase voltage=V.
  • a) 77.9 V
  • b) 77.6 V
  • c) 77.2 V
  • d) 77.8 V
Q.8
The slope of the V-I curve is 1.1°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.
  • a) .019 Ω
  • b) .036 Ω
  • c) .075 Ω
  • d) .084 Ω
Q.9
If induction motor rotor power is 157.5 KW and gross developed power is 79.9 KW, then rotor ohmic loss will be _________ KW.
  • a) 77.5
  • b) 77.6
  • c) 76.9
  • d) 77.1
Q.10
The power factor of a squirrel cage induction motor generally is ___________
  • a) .6-.8
  • b) .1-.2
  • c) .2-.4
  • d) .5-.7
Q.11
Calculate the active power in a .H inductor.
  • a) 1.535 W
  • b) 0 W
  • c) 2.484 W
  • d) 1.598 W
Q.12
Calculate the time period of the waveform i(t)=sin(πt+6π÷4)+sin(πt+5π÷6).
  • a) 2 sec
  • b) 4 sec
  • c) 5 sec
  • d) 3 sec
Q.13
Calculate the total heat dissipated in a rotor resistor of 14.Ω when .A current flows through it.
  • a) 6.45 W
  • b) 6.01 W
  • c) 6.78 W
  • d) 6.98 W
Q.14
Calculate mark to space ratio if the system is on for 4.3 sec and off for 78.2 sec.
  • a) .054
  • b) .047
  • c) .039
  • d) .018
0 h : 0 m : 1 s