Turning a circuit off...without touching it [closed]

Question

Just a curiosity question;

Is it possible to reduce current (to almost zero) in the following complete, simple circuit without making ANY physical contact with it?

Supposing this can be achieved by a certain procedure, say X. Then X must:

-Be practical (at a small, DIY scale)

• Not involve any significant change in temperature (not more than 10°C)

• Not involve any deformation/alteration of the circuit or any of it's components.

• Be able to stop current for a good deal of time (at least an hour)

• Be reversible; i.e- the current ought to flow in the circuit again once X has been stopped or reversed.

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P.S- I'm not sure, but since any physical contact is a big no-no, electromagnetic induction may (somehow?) offer a way out.

EDIT :

I believe the post generated some misunderstanding (I appreciate what you guys suggested in the comments, but that isn't what I'm looking for); so I'll make it clear here:

I've already provided a diagram of the circuit I have in mind...and one of the conditions was:

Not involve any deformation/alteration of the circuit or any of it's components.

Meaning; The original circuit must remain intact...no rewiring or replacing of any of those components. However it may be incorporated into another, larger circuit.

For example, if my original question did not have the temperature or deformation constraint, I'd consider inducing Eddy currents in (a part of) the circuit's wiring. That would possibly increase the temperature of the wiring, and thereby increase it's resistance (much like an induction furnace).

Also, if it's any help, I plan on actually carrying this out...so yeah, the circuit (and its components) aren't idealized. Of course I hope to do this on a fairly small scale (simple circuit with about 2 feet of copper wiring).

Answer 1

Just a curiosity

Generate a rising magnetic field that induces in the circuit loop a voltage that is equal and opposite to the driving voltage from the battery. This then stops current flow. It's not very practical for holding off current for more than a few seconds (of course) unless you used superconductors.

\$V_{INDUCED} = N\dfrac{d\Phi}{dt}\$ where N = 1 i.e. the loop of the circuit.

\$\dfrac{d\Phi}{dt}\$ is produced by applying a voltage across a loop of wire - a constant rising flux is produced.

Note that the following constraint was edited into the question after I provided my answer above: -

Be able to stop current for a good deal of time (at least an hour)

Given that all that is shown in the question is a schematic, there is nothing stopping the implementation of that circuit to involve looping the lightbulb feed circuit around 3,600 times (yes I know I'm stretching it a bit). This makes the induced voltage 3,600 times bigger and therefore the rising flux needed to "hold-off the battery voltage can be 3,600 times smaller and this might be able to be generated for an hour.

If it could be done previously for 1 second then it could be done now for 1 hour.

Also note that my answer isn't about inducing eddy currents in the wiring; it's all about Faraday's Law of induction. Having said that some eddy currents would inevitably be induced but use of thin wires pretty much would make this a secondary effect.

Answer 2

As you've posted a picture of an OPEN circuit, I'd hazard that you've already accomplished the task of reducing current to zero.

As a more direct answer to your question: Yes.