Question

To obtain power from the current in the wire of your vacuum cleaner, you place a loop of wire near it to obtain an induced emf. How do you place and orient the loop?

a) Parallel to the wire, with the same direction of current flow.

b) Parallel to the wire, with the opposite direction of current flow.

c) Perpendicular to the wire.

d) Diagonally to the wire.

Answer 1

To induce the greatest emf in a loop of wire from the current in a vacuum cleaner wire, the loop should be positioned perpendicular to the wire. This aligns with both Faraday's law of induction and Lenz's law, which provides directionality to the induced current. Option c is the correct answer.

Step-by-step explanation:

In the scenario of inducing an electromotive force (emf) using a wire loop from the current in the wire of a vacuum cleaner, the orientation of the loop plays a crucial role. To maximize the magnetic flux through the loop and thus induce the greatest emf, the loop should be placed perpendicular to the wire of the vacuum cleaner. This arrangement optimizes the change in magnetic flux when the current in the primary wire changes, according to Faraday's law of electromagnetic induction.

Furthermore, Lenz's law, which provides directionality to the induced emf, states that the induced current will flow in such a way as to oppose the change that produced it. Therefore, for a loop of wire to induce emf, it should be placed perpendicular to the wire of the vacuum cleaner, which corresponds to option (c).