Answer / surender rawat

Ohm's law applies to electrical circuits; it states that
the current through a conductor between two points is
directly proportional to the potential difference (i.e.
voltage drop or voltage) across the two points, and
inversely proportional to the resistance between them.

The mathematical equation that describes this relationship
is: I = {V} / {R}\,

where I is the current in amperes, V is the potential
difference in volts,and R is a circuit parameter called the
resistance (measured in ohms, also equivalent to volts per
ampere).

It is clear that the Ohms law is applicable in case of
purely resistive loads (R) or linear loads. The transformer
constructed with windings on primary and secondary sides
are inductive in nature which are also non-linear. Hence
Ohms law is not applicable to transformers.

Answer / jawad

i found my answer myself.there is nothing to do with
linearity or non linearity.

ohm law states that "voltage is directly propotional
current IF RESISTANCE IS KEPT CONSTANT.


WHAT HAPPENED HERE IS WE DID NOT SATISFY THE CONDITION OF
OHM LAW BY NOT KEEPING THE RESISTANCE CONSTANT.

so in transformer (considering only primary side,u can also
apply it on secondary), when u step up the voltage by tap
changer, actually u r increasing the no of turns which
alternatively means u r increasing the length of total
winding and hence INCREASINGING THE RESISTANCE AND BECAUSE
OF INCREASE IN RESISTANCE, THE CURRENT DECREASES.

HOPE IT WILL SATISFY U PEOPLE.BUT FOR SURE THERE IS NO
OTHER ANSWER.

Answer / manish gupta

I think that correct answer is that ohms law applies to single circuit but in transformer two circuits are electrically neutral so ohms law cannot be applied to two circuits simultaneously.it obeys ohms law separately for primary and secondary windings

Answer / masoom raza

simple in transformer two winding are not connected electrically(they are linked magneticlly) so we
cannot apply apply ohm law between primary and
secondary. but you can apply it to individually
in primary and secondary side.

Answer / kramkumar03

Ohm's Law itself is not satisfying Law of Conservation of Energy under transformation. i have derived electricity principles without Ohm's Law and also derived equivalent mechanical resistance equation.

V = IR ; P = VI and E= VIt etc... are derived from Transformers principles only not from Ohm's Law. 

please go through the following link and get 100% clarification on principles between transformer and Ohm's law.

http://www.theijes.com/papers/v4-i2/Version-3/I42301160189.pdf

get clarification on everything and those inter relations. 
thanks & regards,
Ramkumar K

Answer / kramkumar03

Ohms's law not for Transformer. ohm's law is applicable when the resistance is constant. both Ohm's law and transformer's principles are different.

Ohms's law cannot / could not satisfying Law of conservation of energy under transformation. but Transformer's principles are satisfying law of conservation of energy under transformation.

Transformer's principles = series, parallel circuits under Transformation. {(V∝R + I∝ 1/R)= (V/I ∝R) = {V=IR}} = {V 1/∝ I}

refer the following link for better under standing. and learn about mechanical resistance.
http://www.theijes.com/papers/v4-i2/Version-3/I42301160189.pdf

thanks and regards,

Ramkuamr K

Answer / rajasekhar

so finally what u r saying?ohms law will work only for
resistive(u r ans ).its absolutly wrong.otherwise how can u
write v=j*w*l*i.whats this formula

Answer / blueraja

This seems to be a confusing subject, so I wrote a blog post
on it:
http://www.blueraja.com/blog/node/22#Do_transformers_obey_Ohms_law

I am posting this here not to spam my links, but because
this page is the first result when searching on google, so
perhaps this will clear some of the confusion for future
googlers.

Answer / salman tariq

I think transformer does not obey Ohms law because of the
variation of resistance.....because we have to step up or
step down the voltage by keep on changing the no. of turns
of windings.
(SALMAN TARIQ) U.E.T TAXILA

Answer / n.rajasekhar

hi,
ohms law work for DC as well as AC,butu have to apply for
a single electrical element at a time.lets say apply for TF
primary winding,then based on the applied voltage and
induced volate and winding impendence u can find supply
current.like that for secondary also.where you got wrong in
this.I guess u might have applied ohms law for both primary
and secondary at a time.
Thank you

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