Editing Inductance (section)

===Ideal transformers===
When {{nowrap|<math>k = 1</math>,}} the inductor is referred to as being closely coupled. If in addition, the self-inductances go to infinity, the inductor becomes an ideal [[transformer]]. In this case the voltages, currents, and number of turns can be related in the following way:

<math display=block>V_\text{s} = \frac{N_\text{s}}{N_\text{p}} V_\text{p} </math>
where

{{plainlist|1=
* <math>V_\text{s}</math> is the voltage across the secondary inductor,
* <math>V_\text{p}</math> is the voltage across the primary inductor (the one connected to a power source),
* <math>N_\text{s}</math> is the number of turns in the secondary inductor, and
* <math>N_\text{p}</math> is the number of turns in the primary inductor.
|indent=1}}

Conversely the current:

<math display=block>I_\text{s} = \frac{N_\text{p}}{N_\text{s}} I_\text{p} </math>
where

{{plainlist|1=
* <math>I_\text{s}</math> is the current through the secondary inductor,
* <math>I_\text{p}</math> is the current through the primary inductor (the one connected to a power source),
* <math>N_\text{s}</math> is the number of turns in the secondary inductor, and
* <math>N_\text{p}</math> is the number of turns in the primary inductor.
|indent=1}}

The power through one inductor is the same as the power through the other. These equations neglect any forcing by current sources or voltage sources.