Inductors, Self-Induction, Inductive Reactance, and Impedance Vocabulary

Vocabulary flashcards covering electrical concepts, units, and trigonometric functions related to inductors, self-induction, inductive reactance, and impedance.

Arctangent

Abbreviated arctan and shown on most calculators by the symbol $\tan^{-1}$. The inverse function of the tangent of an angle that calculates what arc has a tangent of the referenced decimal number.

CEMF (counter EMF)

The voltage induced in an inductor by the changing magnetic field. The voltage induced is counter to, or in opposition to, the voltage that produced the original magnetic field.

Cosine

Abbreviated cos. For a given angle other than the $90^\circ$ angle in a right triangle, the trigonometric function that is the ratio between the leg adjacent to the given angle and the hypotenuse.

Henry

Unit of measure for inductance (abbreviated as $H$, symbol used in formulas is $L$). A coil has an inductance of $1\,\text{henry}$ when a current change of $1\,\text{ampere}$ per second causes an induced voltage of $1\,\text{volt}$.

Impedance

The vector sum of the oppositions found in some AC circuits. The vectors may include inductive reactance, capacitive reactance, and resistance. Impedance is measured in ohms and is represented by the letter $Z$ in formulas.

Inductance

The property of an electric circuit displayed when a varying current induces an electromotive force in that circuit or in a neighboring circuit.

Inductor

The name given to an electrical circuit component that exhibits the properties of inductance, such as a coil of wire creating self-induction and a counterelectromotive force (CEMF).

Leakage flux

Flux lines that do not link properly in an inductor. Some flux lines are lost to the surrounding space and do not complete the magnetic path, reducing the overall magnetic field and the resulting inductance.

Permeability

The degree to which a material focuses magnetic lines of flux, or the ease with which magnetic lines of force distribute themselves through a material. It is a factor compared to air (permeability factor of 1) with no unit of measure, represented in formulas by the lowercase Greek letter mu ($\mu$).

Self-inductance

The property of an electrical component (such as a coil of wire) to induce a voltage into itself as the current through the component changes.

Sine

Abbreviated sin. For a given angle other than the $90^\circ$ angle in a right triangle, the trigonometric function that is the ratio between the leg opposite the given angle and the hypotenuse.

Tangent

Abbreviated tan. For a given angle other than the $90^\circ$ angle in a right triangle, the trigonometric function that is the ratio between the leg opposite the given angle and the leg adjacent to the given angle. Also equal to the sine of the given angle divided by the cosine of the given angle.

Vector sum

The binary vector operation that yields a vector of which the length and direction are represented by the diagonal of a parallelogram of which the sides represent the given vectors being added.