Answer / satendra

On increasing the voltage the current will also be increase (as the res. is constant)in turn flux will also be increase.
But after the saturation point on increasing the voltage the current will go infinite momently. This point is called KNEE-POINT. After the knee point there are a more chances to get the coil as a permanent magnet. So we never perform the test upto knee-point.

satendra.svnit@gmail.com

Answer / chetan sharma

10 % increase in voltage gives you 50 % increase in
excitation current is called knee point voltage.
To measure this first demagnetise the CT and apply
voltage gradually from secondary keeping primary
winding open circuited. while doing this above
phenomeneo will be obsesrved.

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