Answer / jonathan r. lambert

Normally, when power is applied to a transformer the
resulting primary current will be the vector sum of the
primary impedance and the reflected (turns ratio squared)
secondary impedance. However, since the secondary impedance
is infinite at no-load the reflected secondary impedance
will not influence the primary current and the primary
current will be the result of only the primary circuit
impedance. This no-load primary current is referred to as
the primary magnetization current and represents the
current used to excite the transformer's magnetic field
that links the primary and secondary windings - typically
1% to 5% of the full rated load current. Applying a load to
the transformer secondary will result in a primary current
with two components, the reflected secondary current and
the primary magnetization current.

Answer / gunasekaran

no load current is used only for energising the core so it
is 1-2% of full load current

Answer / san

no load current is only d 3-5%of full load current.if
alternating current is applid to d primary then no load
current wl flow through only primary circuit since
secondary is open circuitd.whn load is connected to the
secondary then current wl flow through the secondary
aswell..thats y we cn conclude that no load is smaller than
full load currents..

Answer / masoom raza

when secondary is open circuit the current in primary
is low i.e only magnetizing is present to create flux
in core.but when load is connected in secondary side it
produces its own ampere turn N2I2 which reduces the flux
in core . in order to maintain the flux constant, primary current increases to balance N2I2 i.e
N1I1=N2I2(neglecting magnetizing current)
therefore primary current increases when load
is connected.

Answer / azam

No load pr-current of a transformer is only 1-3% of FL
current because when supply applied 2 t/f it produce
alternating flux which induces emfs in primary & sec wdgs
with in the fraction of second. where as in the case of motor
starting current drawn by it is very high due 2 no presence
of back emf

A separately excited dc motor having 2 ohm armature resistsance draws a current of 10A and torque developed is 20 Nm under rated field condtion. the speed of the motor under the rated field condtion , when it is connected to a 100V DC source and delivering 10Nm torque....

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