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

Inverting integrator circuit, Q. Consider the inverting integrator circuit ...

Q. Consider the inverting integrator circuit shown in Figure. Let C = 0.4µF and R = 0.1M. Sketch v o for a period of 0.5 s after the application of a constant input of 2 V at the

Name 5 different addressing modes, The five addressing modes are given belo...

The five addressing modes are given below: Immediate, Register, Direct, Implied addressing modes           Register indirect,

What is the procedure of binary division, Q. What is the procedure of Binar...

Q. What is the procedure of Binary Division? The Binary division is the repeated process of subtraction, just as in decimal division. Signed Numbers Representation If w

Dc link scherbius drive - motor control , DC Link Scherbius Drive This ...

DC Link Scherbius Drive This type of scheme is shown in figure. This circuit  allows both  sub synchronous  and super synchronous speed control. In case  of sub synchronous spe

Matlap code, matlap code to solve the fast decoupled method

matlap code to solve the fast decoupled method

RC coupled amplifier, what is the reason for reduction in low frequency and...

what is the reason for reduction in low frequency and high frequency regions in the frequency response of an Rc coupled amplifier?

Elucidate the working of broad band ISDN, Q. Elucidate the working of broad...

Q. Elucidate the working of broad band ISDN? Ans: BISDN Configuration: Figuredemonstrates how access to BISDN network is accomplished. Every peripheral device is interfaced

Find the resistance of 1 km of copper cable, Find the resistance of 1 km o...

Find the resistance of 1 km of copper cable having a diameter of 10 mm if the resistivity of copper is 0.017 x 10 -6 Ωm.

Calculate the generator emf , Q.  The armature of 6 -pole dc generator has...

Q.  The armature of 6 -pole dc generator has a wave winding containing 664 conductors. Calculate the generator emf when flux per pole is 0.06 weber and the speed is 250 rpm. At wh

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