DOL starting of induction motors is usually restricted to? Mark as favorite Copy Link low horse power motors variable speed motors high horsepower motors high speed motors Check Answer
A pump induction motor is switched on to a supply 30% lower than its rated voltage. The pump runs. What will eventually happen? It will? Mark as favorite Copy Link stall after sometime stall immediately continue to run at lower speed without damage get heated and subsequently get damaged Check Answer
In a three-phase induction motor? Mark as favorite Copy Link iron losses in stator will be negligible as compared to that in rotor iron losses in motor will be negligible 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 Check Answer
A 500 kW, 3-phase, 440 volts, 50 Hz, A C. induction motor has a speed of 960 r.p.m. on full load. The machine has 6 poles. The slip of the machine will be? Mark as favorite Copy Link 0.01 0.02 0.03 0.04 Check Answer
Lubricant used for ball gearing is usually? Mark as favorite Copy Link graphite grease mineral oil molasses Check Answer
Insertion of reactance in the rotor circuit? Mark as favorite Copy Link reduces starting torque as well as maximum torque increases starting torque as well as maximum torque increases starting torque but maximum torque remains unchanged increases starting torque but maximum torque decreases Check Answer
In a star-delta starter of an Induction motor? Mark as favorite Copy Link resistance is inserted in the stator reduced voltage is applied to the stator resistance is inserted in the rotor circuit applied voltage per stator phase is 57.7% of the line voltage Check Answer
The probable reason for an induction motor running too hot could be? Mark as favorite Copy Link low voltage uneven air gap clogged ventilating ducts any of the above Check Answer
A 3-phase slip-ring induction motor is always started with? Mark as favorite Copy Link a starting winding squirrel cage winding no external resistance in rotor circuit full external resistance in rotor circuit Check Answer
In the squirrel-cage induction motor the rotor slots are usually given slight skew? Mark as favorite Copy Link 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 Check Answer