A 3 phase induction motor connected from a 3 pjhase, 50Hz AC supply runs at 720rpm and has slip 4%. The number of poles in motor are _____.

Related MCQs

• A 50Hz 20 poles 3 phase I.M. has a full load slip 1.33%. Its rotor impedance per phase on standstill is 0.02+j0.3ohms. Then the ratio of starting torque to the maximum torque is____.
• A6 pole 3 phase 50Hz induction motor develops mechanical power of 40Hp and has mechanical losses of 1500W at a speed of 960rpm when connected to 500V. The output available at the shaft is (Take 1HP=746W)
• A 4 pole, 440V, 50Hz induction motor is running at a slip of 4%. The speed of motor 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 50Hz, 8 pole, 3 phase I.M. has a full load slip of 4%. Its rotor impedance per phase on standstill is 0.01+j0.005 ohms. Then the speed at maximum torque is ____.
• A 6pole, 3-ph induction motor is runs at a speed of 960rpm & the shaft torque is 135.7Nm. Calculate the rotor cu loss if the friction and windage losses amount to 150W. The suppy freq is 50Hz.
• A 4 pole, 50Hz induction motor runs at a speed of 1440rpm. The frequency of the rotor induced emf is _____.
• The rotor speed of a 6 pole 50Hz induction motor is 960 r.p.m. The percentage slip is ____.
• A 4-pole, 3-phase induction motor is running at 4 percent slip at full load. If the speed of the motor is 720 rpm, the supply frequency 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.