Find the rotor frequency of an induction motor having 4 poles if the rotor speed is 1746 rpm.

A 3-phase synchronous motor runs at full-load speed of 1200 rpm. If the load is reduced to one-half of rated, calculate its speed regulation.

What is the speed of an induction motor of four poles if the percent slip is 3%?

A three-phase, 50 Hz, 6-pole induction motor runs on full load with slip of 0.04. the rotor standstill impedance per phase is 0.01 + j0.05 Ω. Determine the speed at which maximum torque takes place.

A three-phase synchronous motor of 1,000 kW and 6.6 kV has synchronous reactance of 10 Ω per phase. The efficiency of the motor is 90 %. Neglecting armature resistance. Determine the minimum current.

A three-phase, 60 Hz induction motor has a full-load slip of 5% and full-load rotor current per phase of 10 A. the resistance of its wye-connected rotor is 0.035 ohm per phase. Determine the internal power developed.

The winding of a 4-pole alternator having 36 slots is short by 2 slots. What is the pitch factor?

A three-phase induction motor has a nameplate speed of 1,720 rpm. What is the rotor frequency?

A 220 volts single-phase induction motor draws current of 10 amperes at 0.75 pf. A capacitor of 50 μF is connected in order to improve the power factor. What is the new power factor?

An 8-pole alternator runs at 750 rpm and supplies power to a 6 pole induction motor which has at full load a slip of 3%. What is the full-load speed of the induction motor?

An alternator is supplying a 1 MW load at 0.80 pf lagging. The alternator frequency is 61 Hz at no-load and has a slope of 1 MW/Hz. An additional 0.8 MW load at 0.707 pf lagging is added. What is the operating frequency of the alternator before the load is added? What is the frequency of the alternator after the load is added?

A three-phase, wye connected wound rotor synchronous generator rated at 10 kVA, 230v has a synchronous reactance of 1.2 ohm/phase and armature resistance of 0.5 ohm/phase. What is the percent voltage regulation at full load with 85% lagging power factor?

A 3ϕ wye-connected wound rotor synchronous generator rated at 10 kVA, 230 v has a synchronous reactance of 1.2 ohms/phase and armature resistance of 0.5 ohm/phase. What is the percent voltage regulation at full load with 80% leading power factor?

An induction motor while driving a load takes 350 KW at 0.707 pf lag. An over-excited synchronous motor is then connected in parallel with the induction motor taking 150 KW of power. If the combined pf is 0.9 lagging, calculate the input KVA of the synchronous motor.

A manufacturing plant takes 200 KW at 0.6 pf lag from a 600 V, 60 Hz, 3 phase system. It is desired to raise the pf of the entire system to 0.9 lag by means of a synchronous motor which at the same time to drive a dc generator requiring that the synchronous motor takes 80 KW from the line. What should be the input KVA of the synchronous motor?

A 3 phase, salient pole, wye-connected generator has on per phase basis, Xd = 0.8 pu, Xq = 0.5 pu and Rϕ = 0, based on its MVA and voltage ratings. Find the per unit no-load voltage at 75% full load, unity pf and rated voltage.

A 60 Hz, 8 pole, wye-connected, 3 phase, salient pole generator has 96 armature slots with 4 conductors per slot connected in series in each phase. The coil pitch is 10 slots. If the maximum value of the air gap flux is 60 mWb, determine the KVA rating of the machine if each phase is capable of carrying 650 A.

A 60 MVA, 69.3 KV, 3 phase, wye-connected generator has synchronous reactance of 15 ohms/phase and negligible resistance. The generator is delivering rated load at 80%pf leading and rated voltage to an infinite bus bars. Find the generated voltage/phase in KV.

A 100 hp, 1,750 rpm, 2,300 V, 3 phase motor draws 150 A and produces a torque of 120% of full load value when started at 2,300 V. If a compensator is to be used and 80% of the voltage tap is selected, find the starting torque in lbs-ft.

A 4 pole, 3 phase induction motor has a wye-connected stator winding and runs on a 220 V, 60 Hz supply. The rotor resistance and standstill leakage reactance are 0.1 and 0.9 ohm/phase respectively. The ratio of rotor to stator turns/phase is 2/3. Calculate the torque developed in N-m when running with a slip of 4%.

A 3,300 V, 24 pole, 60 Hz, 3 phase, wye-connected induction motor has rotor resistance and standstill leakage reactance of 0.016 and 0.265 ohm/phase, respectively. Calculate the ratio of the full load torque to the maximum torque developed if full load speed is 296.4 rpm.

Calculate the rotor resistance in ohm/phase on a 6 pole, 60 Hz, 3 phase induction motor if the motor develops a maximum torque of 300 N-m at 780 rpm. The rotor standstill leakage reactance is 3 ohms/phase.

Two 60 Hz motors are connected in concatenation to drive a load. If machine 1 has 6 poles and machine 2 has 4 poles, calculate the speed in rpm for a slip of 5%.

A 15 hp, 400 V, 3 phase, wye-connected synchronous motor has full load efficiency of 90%. The synchronous reactance is 3 ohms/phase. If the motor operates at full load at 0.8 pf leading, find the torque angle in electrical degrees.

A synchronous motor absorbing 60 KW is connected in parallel with a load of 240 KW having a lagging pf of 0.8. If the combined load has a pf of 0.9 lagging, what is the value of the leading KVAR supplied by the motor?

An industrial plant has an average load of 400 KW at 0.707 pf lag. An additional load of 200 hp over-excited synchronous motor is added to the plant to improve the pf to 95% lagging. Calculate the approximate operating pf of the synchronous motor.

A squirrel-cage motor develops 80 lb-ft of starting torque when the 50 percent tap on compensator is used to start the machine by the reduced-voltage method. What starting torque will be developed l the 65 percent tap is used?

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.

A 3ϕ, 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?

Two alternators operating in parallel supply 2500 KW to a load at a power factor of 80% lagging. If one machine delivers 1200 KW at a power factor of 95% lagging, what is the power supplied by the other machine?