The factors that affect the inductance of a coil vary. Many differently constructed coils can have the same inductance. Inductance depends on the degree of linkage between the wire conductors and the electromagnetic field. In a straight length of conductor, there is very little flux linkage between one part of the conductor and another. Therefore, its inductance is extremely small.
Conductors become much more inductive when they are wound into coils.
This is true because there is maximum flux linkage between the conductor turns, which lie side by side in the coil. An inductor has an inductance of 1 henry if an EMF of 1 volt is inducted in the inductor when the current through the inductor is changing at the rate of 1 ampere per second. Normally, this resistance is small. However, since some inductors are designed to carry relatively large amounts of current, considerable power can be dissipated in the inductor even though the amount of resistance in the inductor is small. This is wasted power called copper loss.