Answer / shiva

kva is active power+ reactive power
the really used power is active power only.
which is v*i*cos pi.
but we dont know user's power factor so ratings are kva for t/f.

Answer / biswaranjan das

Transformers Are Rated In Kva Because Generally There Are Two Losses In A Transformer I.e Core/iron Loss & copper Loss Due To Transformer Is A Stready Device So Their Is No Loss Of Mechanical . Due To the Core Losses Depends upon Voltage(v) & copper Losses Depends Upon Current(A) So The total Losses Depends Upon VA I.e KVA .

Answer / sandip paul

Trafo losses depends on voltage and current only. voltage
influences the core loss or no load loss and current or
load influences the copper loss. no loss depends on power
factor of the load. thus efficiency is mainly governed by v
and I only. hence o/p whis is the ratio of (i/p - losses)/
i/p is controlled by v and I. Hence trafo rating is defined
in KVA no KW.

Answer / rams

due to the losses of transformer dependas on the current
and voltage.

Answer / pramod pandey

transformer rating in
kva because power
factor of transformer
is always depended on
other load.

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