3P Induction Motors

A test used to determine the equivalent resistance of an induction motor is _.

In running condition the rotor reactance of a \(3\Phi\) induction motor is proportional to

The voltage applied to the stator of a three phase, 4 pole induction motor has a frequency of 50 Hz. The frequency of the emf induced in the rotor is 1.5 Hz. Determine the speed at which motor is running.

In a winding of a \(3\Phi\), 6 pole induction motor, the space angle between two consecutive phases is

A \(3\Phi\), 6 pole, 50 Hz induction motor develops 3.73 kW at 960 rpm. What will be the stator input if the stator loss is 280 watts?

If starting voltage of a SCIM is reduced to 50% of its rated vlue, torque developed is reduced by _ percent of its full load value.

A change of 5% in the supply voltage of a three-phase induction motor will produce to its torque a change of approximately _______.

A three-phase 4-pole 50 Hz induction motor has a rotor resistance of 0.020 ohm per phase and standstill reactance of 0.5 ohm per phase. Calculate the speed at which the maximum torque is developed.

A 50 Hp, 440 V, 3-phase, 60 Hz,6-pole squirrel cage induction motor is operating at full load and 0.8 p.f. The full load efficiency is 85% and the percentage slip is 5 %. Determine the full load torque.

The voltage applied to the stator of a three-phase, 4-pole induction motor has a frequency of 50 Hz. The frequency of the emf induced in the rotor is 1.5 Hz. Determine the speed at which motor is running.

The rotor of a 220 v, 60 Hz, 4-pole induction motor has a power input of 80 kW. It is observed that the rotor emf makes 90 cycles per minute, Calculate the rotor copper loss.

To reverse the direction of rotation of a three-phase induction motor, it is necessary to

A six-pole three-phase 440-v, 60 HZ induction motor develops 10-HP at 1,150 rpm, the power factor being 80% lagging. Stator and core losses amount to 400 w and 350 w, respectively. Frictional losses amount to 0.5-hp. Calculate motor line current.

The rotor resistance of an 8-pole, 50 HZ, wound rotor induction motor is 0.5 Ω per phase The speed of the motor is 720 rpm at full load Determine the external resistance to be connected with the rotor circuit to reduce the speed to 680 rpm for full-load torque. 2 Ω

For an ac motor, the frequency is 60 Hz and the speed is 300 rpm. What is the number of poles?

If the speed of an Induction motor increases, what happens to the rotor frequency?

A 7.5 HP, 500 v three-phase induction motor is developing its full-load output at 960 rpm. The starting torque is equal to the full-load torque. What will be the starting torque if the supply voltage fall to 400 volts?

A 50 HP, 440 v, 3-phase, 60 Hz, 6-pole squirrel cage induction motor is operating at full-load and 0.8 power factor. The full-load efficiency is 85% and the percentage slip is 5%. Determine the full-load torque.

A three-phase, 440 v, 50 Hz, 6-pole induction motor running at 950 rpm takes 50 kW at a certain load. The friction and windage loss is 1.5 kW and stator losses = 1.2 kW. Determine the output from the rotor.

If supply voltage is changed by 5% for a 3ɸ induction motor, its torque will have a change of