Answer / asmita

For calculation of efficiency of a T/F it is essential to
carry out Open Ckt. n Short Ckt test( As we can not load
each n every t/f to its rated capacity this will consume a
lot of power.)From O.C.test we can find iron losses of T/F
& from S/c test we can find full load or at any load copper
losses.
For these Electrodynamometer type wattmeters should be used
as it is very sensitive device n Power factor during this
test is very low.

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