For a specified input voltage and frequency, if the equivalent radius of the core of a transformer is reduced by half, the factor by which the number of turns in the primary should change to maintain the same no load current is Here radius means the radius of the equivalent circular core cross-section. Keep magnetic path length and linear permeability fixed; neglect core loss, leakage and winding resistance.
2
With fixed magnetic path length and permeability, Lm=μN²A/ℓ. Halving the equivalent cross-sectional radius divides A by4. At fixed voltage and frequency, unchanged magnetizing current requires unchanged Lm, hence Nnew²/4=Nold². Thus Nnew=2Nold.
Important Questions from Transformer Construction
The core of a transformer is laminated to prevent:
What is the type of transformer used in home inverters to power from a 12V battery?
The thickness of lamination (which reduces eddy current loss) in electrical machine varies from:
(Select the closest range)
If two coils are magnetically coupled and if the entire flux produced by one coil is linked with another coil, the coefficient of coupling k will be:
Frequency of induced voltages in 1-phase transformer is constant because _______.
