Q.1
A 3-phase slip ring motor has
  • double cage rotor
  • wound rotor
  • short-circuited rotor
  • any of the above
Q.2
The starting torque of a 3-phase squirrel cage induction motor is
  • twice the full load torque
  • 1.5 times the full load torque
  • equal to full load torque
  • All of above
Q.3
Short-circuit test on an induction motor cannot be used to determine
  • windage losses
  • copper losses
  • transformation ratio
  • power scale of circle diagram
Q.4
In a three-phase induction motor
  • iron losses in stator will be negligible as compared to that in rotor
  • iron losses in motor will be neg¬ligible as compared to that in rotor
  • iron losses in stator will be less than that in rotor
  • iron losses in stator will be more than that in rotor
Q.5
The torque of a rotor in an induction motor under running condition is maximum
  • at the unit value of slip
  • at the zero value of slip
  • at the value of the slip which makes rotor reactance per phase equal to the resistance per phase
  • at the value of the slip which makes the rotor reactance half of the rotor
Q.6
In the squirrel-cage induction motor the rotor slots are usually given slight skew
  • to reduce the magnetic hum and locking tendency of the rotor
  • to increase the tensile strength of the rotor bars
  • to ensure easy fabrication
  • none of the above
Q.7
In three-phase induction motors sometimes copper bars are placed deep in the rotorto
  • improve starting torque
  • reduce copper losses
  • improve efficiency
  • improve power factor
Q.8
The complete circle diagram of induetion motor can be drawn with the help of datafound from
  • noload test
  • blocked rotor test
  • stator resistance test
  • all of the above
Q.9
The shape of the torque/slip curve of induction motor is
  • parabola
  • hyperbola
  • rectangular parabola
  • straigth line
Q.10
A change ofof supply voltage to an induction motor will produce a change ofappromimately
  • 4% in the rotor torque
  • 8% in the rotor torque
  • 12% in the rotor torque
  • 16% in the rotor torque
0 h : 0 m : 1 s