Answer / gajendra singh

50Hz transformer has large size as for the fixed kva but as the frequency increase and kva fixed than size of x-mer decrease.
because of B-H loop magenetation characteristic

Answer / amrit

He is talking about same KVA t/f.

we r not changing anything but the size... how?
keeping voltage per turn as same in both cases..

we decrease the flux in same proportion as the freq.
increased to keep freq.*flux = const.
now flux decreased reduce the area of the core to keep flux
density same.
Hence size of t/f will b small with high freq.

Answer / hardik (tata chemicals ltd)

As above V/f= flux
1) in case of increase fqr flux is inversely praposnal to
friqunce (vtg = constant) so flux will be reduce so related
to core losses also decrease size of core also we can
decrease..but in this case as per emf equation vtg is also
praposnal to flux so we have to increase wdg turns so size
of all bulk of X'mer become big ,in short it is true size
is inverse praposnal to frequnce but we can not get much
different b'wen as above X.mers

Answer / lucky

size is inversily proportional to frequency...
so 50hz transformer will be larger in size

Answer / er. ankush miglani 9718151073

Mr. Mohh. Shahid
if v/f=flux
then fr is inversly proportional toflux
then if u increase the fr the flux will decrease
and so the core area also decreases.

all this is for the constant voltage

but for the constant flux the fr is directly proportional
to the voltage

so if the voltage increases the insulation increases and
hence the size of the transformer increases.
then in both the casesthe action is opposite

then how can u say that the size of the transformer
increases.
check it out

Answer / mohd shahid

See V/F= flux
Now Case I : Voltage is constant

if we increase the frequency thn flux will increase which
ultimately increases the hysteriss loss so in order to
dessipate the loss we hav to increase the transformer size.

NOW Case II: Flux is constant

In this case also size of transformer will increase with
increase in frequency bcoz voltage will increase in order
to maintain the constant flux. Hence more insulation will
be reqd so size ultimately increases.

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