Magnetic fields Key Terms

flux-time graph

A graphical representation showing the relationship between magnetic flux and time, illustrating how flux changes over a period.

emf-time graph

A graphical representation that depicts the induced electromotive force (emf) as a function of time, indicating how emf varies with changing magnetic conditions.

Alternating Current (AC)

An electric current that reverses direction periodically, characterized by its frequency and peak value.

Frequency

The number of cycles of alternating current that occur in one second, measured in hertz (Hz).

rms value

The root mean square (rms) value is a statistical measure of the magnitude of a varying quantity, commonly used for alternating current (AC) and voltage.

alternating current (AC)

A type of electrical current that periodically reverses direction, characterized by its frequency and peak value.

AC graph interpretation

The process of analyzing the characteristics of alternating current graphs, including amplitude, frequency, and phase relationships.

peak value

The maximum value of voltage or current in an alternating current waveform, indicating the highest point of the graph.

RMS value

The root mean square (RMS) value of an alternating current (AC) is the effective value of the current that delivers the same power to a load as a direct current (DC) of the same value.

Power in AC circuits

The power in an AC circuit can be calculated using the formula P = I_rms × V_rms, where P is the power, I_rms is the root mean square current, and V_rms is the root mean square voltage.

transformer action

The process by which a transformer transfers electrical energy between two or more circuits through electromagnetic induction, utilizing changing magnetic flux.

changing magnetic flux

The variation of magnetic field strength over time in a given area, which induces electromotive force (emf) in a conductor according to Faraday's law of electromagnetic induction.

Transformer Turns Ratio

The ratio of the number of turns in the primary coil to the number of turns in the secondary coil, used to determine the relationship between primary and secondary voltages.

Induced EMF

The electromotive force generated in a circuit due to a change in magnetic flux, as described by Faraday's law of electromagnetic induction.

Transformer Efficiency

The ratio of useful power output to total power input, expressed as a percentage.

Power Conservation in Transformers

The principle that the power input to a transformer equals the power output, assuming no losses.

transformer efficiency

The ratio of useful power output to total power input in a transformer, expressed as a percentage.

power transmission

The process of transferring electrical energy from power plants to consumers through transmission lines.