I wanted to ask a theoretical question. Can someone please explain me how wires connected together in a house circuit do not flow electricity due to induction, as one of the wires is live (the wire which supplies current to the switch) even if the circuit is off?


3 Answers 3


"Induction" (in electrical terms) is creating current in a conductor by a moving magnetic field. AC (alternating current) creates a moving magnetic field. To transfer non-negligable amounts of energy between the wires in the walls of a house, you would need high frequencies. Much higher than the frequency used in household wiring.


Electromagnetic induction is limited by keeping the loop areas small and putting all the wires of a circuit through the same holes, and inside the same conduits - not dividing the circuit to make a physical loop. You only get electromagnetic induction when he circuit is on, when its off there's no current flowing and no path for it to flow. When it's on the supply voltage is much stronger than any induced voltage so it will be hard to detect.

What could be called electrostatic induction between adjacent conductors is present, (but is normally called capacitance when dealing with AC circuits) , and does sometimes pose a problem, causing high efficiency lamps to flicker, blink, or glow faintly when the circuit is off. This is also called "Phantom Voltage". It can also light up non-contact voltage detectors and neon indicators, register on multimeters, and even give very small electric shocks.


"Induction" is the coupling of electrical signals between (more or less) adjacent wires. The coupling will only occur if there is current flowing through the "sending" wire, and there is a "load" on the "receiving" wire so that the received current has somewhere to go.

  • That "load" can by design be the "wire" itself via eddy currents, particularly when the "wire" is shaped like cookware on an induction stove. Jul 5 at 3:05

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