Calculate motor efficiency, Electrical Engineering

Assignment Help:

1. A self excited shunt generator supplies a load of 12.5 kw at 125 volts. The field resistance is 25 ohms and the armature resistance is 0.2 ohms. The total voltage drop because of brush current and armature reaction at this load is 3 volts. Calculate the induced armature voltage.

2. A 6 pole lap-wound armature having 720 conductors, rotates in a field of 20.35 mWb. (a) If the induced current is 72 A, what is the torque developed by armature? (b) If the induced armature voltage is 410V, what is the motor speed?

3. A shunt motor runs at 1100 rpm at 230v and draws a line current of 40 A. The output power(at the shaft) is 10.8 h.p. The various losses are core loss, 200W: friction and windage loss 140W: electrical loss due to brush contact, 32W: stray load loss, 31W. The armature and field-current resistance are 0.2 ohms and 220 ohms respectively. Calculate (a) motor efficiency, (b) the speed if the output power is reduced by 50%.

4. A 4 pole motor is lap wound with 728 conductors and has a flux of 25 mWb per pole. The armature takes 50 A in current: the resultant demagnetizing effect due to armature reaction reduces the air gap flux by 5%. Calculate the developed torque.

5. One of three fuses protecting a 3-phase electric heater rated at 200kW, 600 V is removed so as to reduce the heat produced by the boiler. What power does the heater develop under these conditions?

 


Related Discussions:- Calculate motor efficiency

Kalman Filter, Kalman filter implementation assignment

Kalman filter implementation assignment

Full wave bridge rectifier circuit , Construct a full wave bridge rectifier...

Construct a full wave bridge rectifier circuit and connect it to the transformer output. What is the Output Voltage and Frequency?

Read-and-write memory, Q. Read-and-write memory? Writing is the same as...

Q. Read-and-write memory? Writing is the same as storing data intomemory and reading is the same as retrieving the data later. RAM is said to be volatile because its contents a

Electrical starter motor, ELECTRICAL STARTER MOTOR This usually consist...

ELECTRICAL STARTER MOTOR This usually consists of a heavy duty, compound wound, DC motor, which draws its electrical supply from an external source. The motor works in conjunc

Explain the action of a pn-junction with bias, Q. Explain the action of a p...

Q. Explain the action of a pn-junction with bias. Consider both the forward bias and the reverse bias, and use sketches wherever possible.

Cro, what is cro ?

what is cro ?

Literature review on co2 positive displacement pump, Ask question introduc...

Ask question introduction of co2 single stroke positive displacement pump using cam and follow system to transfer co2 into small cylinders

Determine the synchronous speed in revolutions per minute, Q. Determine the...

Q. Determine the synchronous speed in revolutions per minute and the useful torque in newton- meters of a 200-hp, 60-Hz, six-pole synchronous motor operating at its rated full load

Overview of decimal number system, Q. Can you give some Overview of Decimal...

Q. Can you give some Overview of Decimal Number System? The Decimal Number System uses base 10 and It includes the digits from 0 through 9. The weighted values for each positio

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd