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

List few applications of microprocessor-based system, List few applications...

List few applications of microprocessor-based system. It is used: i. For measurements, display and control of current, voltage, temperature, pressure, etc. ii. For traff

Explain basic working of integrators, Q. Explain basic working of Integrato...

Q. Explain basic working of Integrators? Figure shows a noninverting integrator, which can be seen to be a negative impedance converter added with a resistor and a capacitor. N

Meter field testing - sealing points, Meter Field Testing - Sealing Points ...

Meter Field Testing - Sealing Points The meter seal should be tamper proof. The consumer should be briefed about seals. The sealing of all metering systems should be completed

Measuring equipment of ac-dc voltage and waveforms, Procedures and methods ...

Procedures and methods of the experiments A).      In order to measure the true RMS values of the currents and voltages, students used the true RMS multimeter. It requires two

Calculate the value of resistor, Calculate the value of resistor: 1.  ...

Calculate the value of resistor: 1.  What are the significant differences in the way ammeters and voltmeters are connected. If an ammeter reads 2.5 A for a period of 4 minutes

Integrated circuit components, You are required to design and document the ...

You are required to design and document the hardware design for Lift Control Unit (LCU) as required by the questions/specification in section 2 above, based on a 68HC12D60 microcon

Find the duration t of the pulse, By a simple time multiplexing of natural ...

By a simple time multiplexing of natural samples over a single line, a large radar site transmits 85 analog signals, each with 200-Hz bandwidth. If the sampling is done at twice th

Find the ratio of amplifier gain, The input to the satellite system of Figu...

The input to the satellite system of Figure 1 is a step function θ c (t) = 5u(t) in degrees. As a result, the satellite angle θ(t) varies sinusoidally at a frequency of 10 cycles p

1-phase full bridge inverter will rl load , 1- Phase Full  Bridge  inver...

1- Phase Full  Bridge  inverter will RL Load For a  resistive load R the load  current  wave form  will be  identical with load  voltage wave form  and feedback  diodes will

Explain the different types of multivibrators, Explain the different types ...

Explain the different types of multivibrators ? Multivibrator is basically  a two-stage amplifier with output of one supplied back to the input of the other . Multivibr

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