What signifies that a coil has an inductance of 1 henry?

A coil has an inductance of 1 henry when a change of 1 ampere in the current flowing through it induces a voltage of 1 volt across its terminals. This relationship is defined by the formula for inductance, which states that the induced voltage ( V ) is proportional to the rate of change of current ( \frac{di}{dt} ), specifically ( V = L \frac{di}{dt} ). Thus, if the inductance ( L ) is 1 henry and the current changes by 1 ampere per second, the induced voltage will be 1 volt.

This understanding of inductance is fundamental in electrical engineering, as it describes the behavior of coils or inductors in response to changes in current. The other options imply various relationships between current changes and induced voltage that do not align with the definition of 1 henry. For example, a change of 2 amperes resulting in 2 volts would suggest an inductance of 1 henry, but it does not directly signify the specific condition described in the question. Similarly, options relating to changes in voltage corresponding to changes in amperes are misalignment with the direct definition of inductance.