Rotor winding of 3 phase I.M. is generally------

Related MCQs

• A 4 pole, 50Hz , 3 phase I M is running at 1425rpm on full load having rotor impedance per phase on standstill as 0.4+j2Ω. The external resistance required in the rotor per phase to get maximum torque at start is ___.
• A 25kW, 3 phase I.M. is running with 6% slip. Its rotor resistance per phase is____ if frictional losses are 850W and rotor current per phase is 65A.
• A 3 phase indution motor is running with slip of 4% hving synchronous speed of 1500rpm. If rotor induced emf per phase in standstill condition is 115.47V and rotor impedance in standstill condition is 0.1+j1 Ω then torque developed ia____.
• A 3 phase induction motor is running with 4% slip. Its rotor input is 10kW then rotor copper losses are
• A 3 phase I.M. is running with 5% slip. Its rotor input is 20kW then its rotor efficiency is ____.
• A 3-phase ,400 V, 4-pole induction motor is fed from a 3-phase, 400V, 50 Hz supply and runs at 1440 rpm. The frequency of rotor emf is
• A 3 phase induction motor running with full load slip of 1.2% and its rotor impedance per phase on standstill is 0.016+j0.265Ω then the ratio of full load torque to maximum torque is
• A 3 phase induction motor is running with full load slip of 1.2% and its rotor impedance per phase is 0.06+j0.265Ω then ratio of starting torque to maximum torque is
• A 3 phase I.M. is running with full load slip of 1.2% and its rotor impedance per phase on standstill is 0.016+j0.265Ω then ratio of full load torque to starting torque is _____.
• A 4 pole, 50Hz , 3 phase I M is running at 1425rpm on full load having rotor impedance per phase on standstill as 0.4+j2Ω. If voltage between the slip rings on open circuit is 520V then the torque developed on full load is ___ Nm.