:: 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                      
Categories >> Engineering >> Electrical Engineering


 Civil Engineering interview questions  Civil Engineering Interview Questions (3124)
 Mechanical Engineering interview questions  Mechanical Engineering Interview Questions (3300)
 Electrical Engineering interview questions  Electrical Engineering Interview Questions (13436)
 Electronics Communications interview questions  Electronics Communications Interview Questions (2385)
 Chemical Engineering interview questions  Chemical Engineering Interview Questions (420)
 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 (165)
 Instrumentation interview questions  Instrumentation Interview Questions (2398)
 Automobile Engineering interview questions  Automobile Engineering Interview Questions (107)
 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 (80)
 Engineering AllOther interview questions  Engineering AllOther Interview Questions (1203)
what will happen if we give a dc supply to a transformer.?
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
# 1
transformer windings will burn 
Is This Answer Correct ?    32 Yes 5 No
# 2
transformer induces e.m.f. due to rate of change of flux ,
which is only possible in a.c. supply in stationary
machines, if we will give d.c. supply as input there will
be no out put & due to core saturation after some time it
will be got damaged(burn).
Is This Answer Correct ?    25 Yes 1 No
D.k. Gupta
# 3
transformer works on mutual induction principal & we no
that an ac current change with time due to which flux
generate. if we provide dc to the transformer their is no
linkage of flux to secondary wdg. hense we will not get
anything in secondary or output
Is This Answer Correct ?    18 Yes 2 No
Vedpraksh Uppadhaya
# 4
When Dc supply is given to primary of transformer it draws
heavy current from the DC source due to absence of back emf
and burnt out.Because the dc current not varying with time
it has constant value throught the period.
(AC is given to transformer the sinusoidaly varying
current creates a sinusoidaly varying flux ,this flux cuts
the stationary primary coils and creats a back emf,
(statically induced emf)this back emf opposes the applied
voltage source to drive current(Lenz law) so current is
limited by this back emf hence no overdrawal of current
from source,this is not happen while applying dc)
Is This Answer Correct ?    7 Yes 0 No
Mayilsamy Ranganathan
# 5
ANSWER:Nothing will happen.But fuse will blown off.

EXPLANATION: While applying DC voltage to the
transformer,there is no induced EMF in the primary &
secondary wdg.(except during switching period, both ON&
OFF).so,the transformer will draw high current from the
supply which detoriate the winding insulation & cause
transformer to burn.But actually this will not
happen .Becoz,the fuse will sacrifice itself to protect
transformer from high current.
Is This Answer Correct ?    7 Yes 2 No
# 6
During the time of switching flux links with primary and secondary of the Transformer voltage induced in primary and secondary after that no voltage induced in primary and secondary. Transformer primary take a large current due to the no back emf. This will damage the transformer Primary and later on secondary
Note - If any Correction please send email
Is This Answer Correct ?    2 Yes 0 No
# 7
according to FLEMI change in flux causes EMF induced in the
so when we give a.c change in flux happence, so EMF is
induced in the conductor.
if we give dc[constant flux],so emf induced is zero.
and winding acts as load and dissipates power in the form
of heat and due to over heat winding burns.
Is This Answer Correct ?    1 Yes 0 No
Ramineni Lakshmi Narayana
# 8
for the first time when u give DC to transformer u will get some volt at the o/p for few seconds, after that no volt is transferred to secondary as because of the explanation give above 
Is This Answer Correct ?    3 Yes 3 No
# 9
When DC applied to transformer ,as the dc voltage is not time varying,it produces a constant flux in primary winding,which links only with primary causes primary to burn. 
Is This Answer Correct ?    1 Yes 2 No
# 10
nothing will happen 
Is This Answer Correct ?    7 Yes 28 No

Other Electrical Engineering Interview Questions
  Question Asked @ Answers
how do skin effect is reduced when hallow cond or stranded cond are used ?   1
A 30KW motor running at 1450 rpm draws 56A, how would you determine if this is correct or not?   3
What will happen if i connect two 3-phase tranformers secondary supply on one bus bar that is R-Y-B-N?   2
what is diffrances between fuse and breaker protection? which one is best? Essar 2
What is the important parts of SF6?   2
string efficient is 100% what is the voltage across the each disk?   1
Why we use three phase world wide why not four phase or five phase being used?   8
if three phase supply is given to single phase transformer, what will happen?   3
what is the per unit cost of generation of electricity at thermal,hydro,desael,solar,gas power plant   1
what is difference between earth and ground?/ Sree-Rayalseema-Green-Energy-Limited-SRGEL 3
what is the formulae for calculating the cable size for a given voltage and current. Bharat-Forge 3
Generally In transformer Tap Changer on HT side, but I have seen in 66KV side in 220/66 KV, 100 MVA, Areva make transformer. Why ?   7
For more Electrical Engineering Interview Questions Click Here 

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