Answer / dolphin

generally different conductors are having different
electron density.if current flows from high
electron density conductor to low density conductor
heat will be produced at the junction due to sudden
change in electron density.to avoid this the two
conductors to be junctioned should have minimum
difference in electron density.in some other cases
contact resistance causes heat if they are not
tightly held together.

Answer / kapil gehlot

when two conductor are joined then a contact resistance is
genrated due to that heat is generated and second reason
would be change of electron density and chnage of
resistivity.

Answer / amol

current passes from one conductor to another conductor, if
cross section area is less then it will take heating of
conductor

Answer / ayub

Because of losses due to the collission of electrons and
also due to the diffrent condutors the metal are diffrent
so losses will take place when passing through the one
conductor to the another diffrent conductor.

Answer / pradeep kumar rawat

at the junction of two conduntor some gap are formed at the
junction point, due to this gap some air take place and
ionised by other ions which is flowing in two conductor,air
between two conductor ionised and current posses through
one conductor to other conductor and heat produces, due to
this at the junction of two conductor heat produced.

Answer / ashwin

The two dissimilar metals behave or contribute a thermocouple. A thermocouple is a junction between two dissimilar metals when subjected to heat generates voltage. This is seebeck effect. The inverse of this effect is Peltier effect. When current is passed through a junction containing two dissimilar metals heat is generated.

For more details on the principle of thermocouple go to link below:

http://en.wikipedia.org/wiki/Thermocouple

From the above link if you can reverse the effects or its causative factors you can minimize this effect.

Answer / aziz_raghib2002

at the junction of the two conductors the conductors will
have different potential due to thier material
characteristics and thats why some P.D and so currentand
heat ie cu losses same material should be used and same
ch/hs material

Answer / naveen gupta

Two different metals have two different conductivity, so
the movements of electrons get obstructed during this
transition. Thats why the heat get generated.

Now to minimize it we need to increase the surface area
depending upon their conductivity levels.

Answer / vishnu p jariwala

Both conductors have differend impedance(Z),And Becose of
resister heat losses is accour That's why...

Answer / j.kesavan

we are use different conductors ,suppose we joint copper and
aluminium busbars using bimetalstrip reduce heat.

i want some interview related questions with their answers which can help for attend the interviews...

0 Answers   Janta Glass,

what is the purpose of neutral grounding resistor (NER) and why?

8 Answers   CBRE, Square Textiles,

3phase lt motor winding how to checking with megger

1 Answers  

hello friends this is krunal here.. i have applied for he officer train in hpcl electrical stream.. any one who have applied before for electrical stream please help me out.. post ur reply to my mail id: krunal_airforce@yahoo.com.. any tips, old questions for paper or any help will do.. plz help me.. your faithfully, Krunal Darji

0 Answers  

How to calculate energy stored in an inductance?

0 Answers  

what you mean by current? what you mean by voltage? what is difference between star and delta connection in motor side?

2 Answers   Adani,

Why Stabilising Resistor used in REF circuit ?

0 Answers  

How does an induction motor start?

0 Answers   Ericsson,

what is ht breaker

8 Answers  

i have 28/32 MVA power transformer with 11/6.6 KC voltage rating and 12%impedance.it have star connection at both side.but it have another thied winding tertiary winding.what is used of this winding. pl tell me

7 Answers  

I have calculated load for an office building which is 1200 KW as all the load is single phase therefore its 1200 kw single phase. Now i have to design Transformer and Generator for this load Please kindly give me exact answer that how much capacity of Three Phase Transformer and Three Phase Generator is required for this load.

3 Answers  

If R and Y terminals are short circuited,then power will cut. we all know that power cannot be stored.what will happen to already generated power at power station?

3 Answers