Self-Inductance, Mutual Inductance, and Transformers

Vocabulary flashcards covering the fundamental concepts and units of self-inductance, mutual inductance, and transformer applications based on the physics lecture.

Self-inductance

A phenomenon where a changing current in a wire causes an induced $EMF$ on itself due to the resulting change in magnetic flux.

Inductance ($L$)

The proportionality constant relating the induced $EMF$ to the change in current over time, expressed in the formula $\text{EMF} = -L \frac{\text{Delta } I}{\text{Delta } t}$.

Henry ($H$)

The SI unit for inductance, which is equivalent to one volt second per ampere ($V \times s / A$).

Mutual inductance

A process involving two circuits where a changing current in a primary coil causes an induced $EMF$ in a second, nearby secondary coil.

Primary coil

The coil in a setup that contains the initial changing current ($I_1$) and acts as the source of the changing magnetic field.

Secondary coil

The coil that experiences an induced $EMF$ ($E_2$) due to the proximity and changing magnetic flux of the primary coil, despite having no $EMF$ source of its own.

Transformer

A special application of mutual inductance used to change the potential difference in an alternating current ($AC$) circuit, often utilizing a common ferromagnetic core.

Step Down Transformer

A transformer designed to decrease potential difference by having fewer turns in the secondary coil ($N_2$) than in the primary coil ($N_1$).

Step Up Transformer

A transformer designed to increase potential difference by having more turns in the secondary coil ($N_2$) than in the primary coil ($N_1$).

Transformer Turns Ratio Equation

The mathematical relationship stating that the $EMF$ in the coils is directly proportional to the number of turns: $\frac{E_1}{E_2} = \frac{N_1}{N_2}$.