The external resistance added in the rotor circuit at start _____.

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 ___.
• External resistance is added to rotor winding of slip ring I.M to --------starting torque
• A shunt motor runs at 500rpm on a 200V circuit. Its armature resistance is 0.5Ω and the current taken is 30A in addition to field current. What resistance must be placed in series with armature circuit to reduce to speed to 300 rpm; the current in armature remains same.
• The rotor standstill resistance and reactance of an induction motor are 0.5Ω and 2.5Ω hence the rotor impedance at 5% slip 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.
• When an induction motor is running at full load, rotor reactance is ------rotor resistance
• The speed of rotating field due to rotor currents relative to rotor surface in an induction motor is
• There is no electrical connection between stator and rotor, still power is transffered from stator to rotor through
• 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