Answer / adeel zafar

voltage induced in a coil depends upon the rate of change
of flux linking it, according to Faraday's law. dc voltage
produces constant flux which does not change with time. so
no voltage can be induced in the secondary winding.

Answer / prayank gupta

faraday's law states that E=∫(dф/dt)
Hypothetically an ideal transformer would work with direct-
current excitation, with the core flux increasing linearly
with time. In practice, the flux would rise to the point
where magnetic saturation of the core occurs, causing a
huge increase in the magnetizing current and overheating
the transformer. All practical transformers must therefore
operate with alternating (or pulsed) current

Answer / sathesh

As we know that v=iz+e1,when dc supply is given the
tfr,there is no induced emf e1 in the tfr, so there is no
oppposition to the supply by the emf induced in the primary
winding, which makes v=iz+0, this makes v=iz => i=v/z,
if v=230v, let z=3ohm, then i=77Amps(app), which leads
more heat in the windings.. cause the burnin of the
transformer, when dc supply is given to tfr...

Answer / shiva

The transformers working in a inducation prinicples.
Secondary induced emf is directely proportional to the rate
of change of primay flux. When transformer is engriesed
from a dc source the core will be continously magenitised.
So core will saturate.

Answer / muthuramalingam

transformer will work liks as electromagnet.

why we are using DC supply in megger?

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