ALLInterview.com :: Home Page            
 Advertise your Business Here     
Browse  |   Placement Papers  |   Company  |   Code Snippets  |   Certifications  |   Visa Questions
Post Question  |   Post Answer  |   My Panel  |   Search  |   Articles  |   Topics  |   ERRORS new
   Refer this Site  Refer This Site to Your Friends  Site Map  Bookmark this Site  Set it as your HomePage  Contact Us     Login  |  Sign Up                      
Google
   
 
Categories >> Engineering >> Electrical Engineering
 
 


 

 
 Civil Engineering interview questions  Civil Engineering Interview Questions (3154)
 Mechanical Engineering interview questions  Mechanical Engineering Interview Questions (3306)
 Electrical Engineering interview questions  Electrical Engineering Interview Questions (13483)
 Electronics Communications interview questions  Electronics Communications Interview Questions (2395)
 Chemical Engineering interview questions  Chemical Engineering Interview Questions (424)
 Aeronautical Engineering interview questions  Aeronautical Engineering Interview Questions (77)
 Bio Engineering interview questions  Bio Engineering Interview Questions (17)
 Metallurgy interview questions  Metallurgy Interview Questions (80)
 Industrial Engineering interview questions  Industrial Engineering Interview Questions (166)
 Instrumentation interview questions  Instrumentation Interview Questions (2409)
 Automobile Engineering interview questions  Automobile Engineering Interview Questions (109)
 Mechatronics Engineering interview questions  Mechatronics Engineering Interview Questions (38)
 Marine Engineering interview questions  Marine Engineering Interview Questions (45)
 Power Plant Engineering interview questions  Power Plant Engineering Interview Questions (81)
 Engineering AllOther interview questions  Engineering AllOther Interview Questions (1207)
Question
In Swinburne's Test on D.C.machines, why the efficiency  is 
more when the machine runs as generator than when it runs as 
motor???
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
The total loss Pl= constant loss(Pk) + variable loss(Pv)
for any DC machine.
For generator, since Ia=Il+If, the efficiency = 1-Pl/
(VtIl+Pl)
For motor, Ia=Il-If , the efficiency =1-Pl/VtIf.

Its obvious that the efficiency value for generator will be
higher than motor, since Pl is not a negligible value.
 
Is This Answer Correct ?    27 Yes 4 No
Lakshmi Devadas
 
Answer
# 2
because of high currents obtained when it is placed as motor & 
Is This Answer Correct ?    43 Yes 23 No
Dharani
 
 
 
Answer
# 3
in motor the supply voltage isopposed by the back emf .soit
draws more current to run the load
but in generator the whole generated emf supplied to the load
 
Is This Answer Correct ?    15 Yes 5 No
Hema
 
Answer
# 4
the output of a generator is more and also the input to the generator will be less and so the efficiency will b more 
Is This Answer Correct ?    15 Yes 8 No
Chaitanya
 

 
 
 
Other Electrical Engineering Interview Questions
 
  Question Asked @ Answers
 
why auto transformer connected in star?   1
Tell me harmfull effects of over voltage,under voltage,spike,surge,transient & noise.   1
Can Dy11 and Dy1 vector group transformers be paralleled?   1
howmany types of compresor is there? and how to calculate compresor capacity?   3
2. The heaviest and lightest strings on a certain violin have linear densities of 3.0 and 0.29 g/m. What is the ratio of the diameter of the heaviest string to that of the lightest string, assuming that the strings are of the same material?   1
What do you mean by creepage distance? Amara-Raja 4
in VFD when freq is reduce the voltage will reduceor not if it will reduced upto ...   8
what is 6 pulse and 12 pulse inverter? Explain brifly   2
how generator generates electricity? Suzlon 1
What is mean by voltage & current.   11
wchich motor we are using in mixer?   4
what are the different functions of mccb, rccb / elccb ?   2
 
For more Electrical Engineering Interview Questions Click Here 
 
 
 
 
 


   
Copyright Policy  |  Terms of Service  |  Articles  |  Site Map  |  RSS Site Map  |  Contact Us
   
Copyright 2013  ALLInterview.com.  All Rights Reserved.

ALLInterview.com   ::  KalAajKal.com