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Proximity effect is based on
Magnetic flux
Voltage
Power
P.F
Magnetic flux
The proximity effect is an electrical phenomenon where the alternating magnetic flux produced by one conductor induces eddy currents in an adjacent conductor. This interaction forces the current to redistribute within the conductor cross-section, effectively increasing the internal AC resistance.
The proximity effect is an electrical phenomenon where the alternating magnetic flux produced by one conductor induces eddy currents in an adjacent conductor. This interaction forces the current to redistribute within the conductor cross-section, effectively increasing the internal AC resistance.
RacтАЛ>RdcтАЛ тАФ The effective AC resistance is higher than DC resistance due to non-uniform current distribution
IeddyтАЛтИЭdtd╬жтАЛ тАФ Induced eddy currents are proportional to the rate of change of magnetic flux
When alternating current flows through two or more adjacent conductors, each conductor is subjected to the magnetic field generated by the others. This time-varying magnetic flux cuts across the neighboring conductors, inducing eddy currents due to Faraday's law of electromagnetic induction. These eddy currents oppose the main current at certain points in the conductor and aid it at others, resulting in non-uniform current density and an increase in the effective resistance.
It is significant in closely spaced transmission lines and multi-core cables.
The effect causes the current density to be higher at the sides of the conductors closest to or furthest from each other depending on the direction of current flow.
It significantly increases the power losses in the system due to the increase in effective resistance.
The effect is negligible for DC as the magnetic flux is constant (dtd╬жтАЛ=0).
None, it is an undesirable phenomenon in power systems.
Provides essential design data for spacing conductors to minimize losses.
Increases the effective resistance of the conductors.
Leads to higher power losses (I2R losses).
Causes non-uniform heating within the conductor insulation.
Design of high-voltage transmission lines.
Configuration of multi-core power cables.
Placement of busbars in switchgear systems.
The skin effect and proximity effect both contribute to the increase of AC resistance over DC resistance.
Option B, C, and D are incorrect because voltage, power, and power factor are outcomes or system parameters, not the physical mechanism behind the flux-based induction of eddy currents.
A is correct тАФ The proximity effect is fundamentally driven by the interaction of time-varying magnetic flux between adjacent current-carrying conductors.
Always remember that skin effect is an 'internal' effect (one conductor), while proximity effect is an 'external' effect (between multiple conductors).