A 440 V, 60 Hz, 6 poles wye connected 3-phase induction motor draws a power input of 85 kW with a line current of 120 A. The core loss is 2.5 kW, F& WL is 1.5 kW. The stator’s resistance between two terminals is 0.4 Ω. Calculate the efficiency of this motor if it runs at a slip of 2.5%

A 220V, 60Hz, 4 pole induction motor has a rotor power developed of 78KW and a rotor power input of 80KW. What is the frequency of the rotor emf in cycles per minute?

An 8-pole alternator runs on 750 rpm and supplied power to a 6 pole induction motor which has a full load slip of 3%. Find the full load speed of the induction motor. Answer: 970 rpm

A 3 phase 60Hz, 60 pole induction motor delivers 25 HP at 1,150 rpm. If the rotor copper loss is 300 watts, what is the rotor power input? a. 7,194 w              b. 6, 194 w b. 8, 194 w             d. 5,194 w

6. Analyzing an AC power outlet: a. Identify the common names for measurements 1, 2, 3, and 4 for this voltage trace. In a country using 220 VAC as standard, what is the peak-to-peak voltage? b. C. A single-phase induction motor draws 4 Amps rms when operating in the country above. What is the apparent power usage? Please note the units. û 0 -û- 3 1 V 4

Q2/A 460 V, 25 hp, 60 Hz, four pole, Y-connected induction motor has the following impedances: R1 = 0.641 2 R2e = 0.332 N %3D X1 = 1.106 2 Mechanical loss is 100 W and core loss is 1 kW for a slip = 2.2%, find: X2e = 0.464 Q Xm = 26.3 Q %3D %3D (a) The speed. (b) The stator current. (c) Power factor (d) The developed and output power (e) The developed and output torque (f) Efficiency

A 110 V, 60 Hz, 6 — pole single phase induction motor 1/3 hp has the following equivalent circuit impedances: RI = 1.52 ohm, R2 = 3.13 ohm and xl =2.10 ohm, x2 =1.56 ohm. Xm=58.2 ohm, The friction, windage and stry losses =16W, the core loss = 35 W. For a slip of 0.05, calculate (a) input current, (b) power factor, (c) developed power, (d) output power, (e) speed (f) in put power (g) air gab power (h) T ind (i) T load (j) efficiency.

There are 72 slots in a 3-phase, 8-pole, 50 Hz, star connected alternator. There are 2 conductors in each slot and all the conductors in a phase are connected in series. Coil span is 150° electrical and the flux per pole is 0.05 Weber sinusoidally distributed. Calculate the emf induced per phase.

A single phase induction motor is rated 5 hp, 75% power factor and 220 volts. What approximate size of capacitor is necessary to raise the power factor to about 98%. O 2.5 KVAR O 2.5 KVAR O 2 KVAR O 3.5 KVAR

A basic one-loop dc generator is rotated at 60 rps. How many times each second does the dc output voltage peak (reach a maximum)?