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Transformer substation does not change
Power
Power factor
Frequency
All of above
All of above
A transformer substation utilizes electromagnetic induction to change voltage levels, but it maintains the fundamental characteristics of the electrical system such as frequency and total active power (minus minor efficiency losses). Consequently, the substation acts as a static device that alters voltage and current levels while keeping the power, frequency, and phase-related properties largely unchanged.
A transformer substation utilizes electromagnetic induction to change voltage levels, but it maintains the fundamental characteristics of the electrical system such as frequency and total active power (minus minor efficiency losses). Consequently, the substation acts as a static device that alters voltage and current levels while keeping the power, frequency, and phase-related properties largely unchanged.
finтАЛ=foutтАЛ тАФ Frequency remains unchanged
PinтАЛтЙИPoutтАЛ тАФ Power remains constant assuming ideal conditions
VsтАЛVpтАЛтАЛ=IpтАЛIsтАЛтАЛ=a тАФ Transformer turns ratio relationship
The transformer operates on Faraday's law of electromagnetic induction. As the AC flux changes in the core, the frequency of the induced electromotive force remains identical to the supply frequency. Since power is the product of voltage and current (P=VIcos╧Х), the transformer scales V and I inversely, leaving the product P and the power factor cos╧Х effectively constant under ideal conditions.
Transformers are static devices, meaning they have no moving parts to change mechanical or temporal parameters like frequency.
The input and output frequency is locked to the grid frequency (50 Hz or 60 Hz).
Power factor is determined by the load impedance; the transformer does not modify the phase angle between voltage and current.
Real power throughput is constant, disregarding small losses (I2R and core losses).
Efficient voltage transformation for long-distance transmission
Isolation of different grid sections
Subject to harmonic distortion if non-linear loads exist
Significant thermal loss at high power ratings
Grid distribution
Industrial power sub-metering
Option A: Power is conserved (Input = Output + Losses), so it is not 'changed' in the sense of transformation.
Option B: Power factor is a function of the connected load and does not change due to the transformer itself.
Option C: Frequency is explicitly determined by the prime mover of the alternator.
D is correct тАФ A transformer is a static electromagnetic device that modifies voltage and current levels while maintaining constant frequency, power (ideally), and power factor.
Always remember that transformers are 'static' devices; anything related to rotation, frequency, or time-domain shifting cannot be altered by a transformer.