Question

How would you shape a given length of wire to give it the greatest self-inductance? The least?

Short answer

Shape the wire into a coil with as many turns as feasible to increase its self-inductance.

Shape the wire into a loop to give it the lowest non-zero self-inductance.

Step-by-step solution

Definition of self-inductance

The tendency of a coil to resist changes in current inside itself is known as self-inductance. When current flows through a coil, an EMF is produced that is proportional to the rate of current flow through the coil.

Explanation

Create a coil with as many turns (minimum diameter) as feasible to enhance the wire's self-inductance. As a result, the surface area through which the magnetic field generated by the wire passes will increase, and the self-inductance will rise.

Make the wire straight to reduce self-inductance. The surface area across which the magnetic field generated by the wire passes will be nearly nil. As a result, the self-inductance will be as low as possible.