# Physics Topic: Alternating Current

Show an understanding and use the terms period, frequency, peak value and root-mean-square value as applied to an alternating current or voltage.

Deduce that the mean power in a resistive load is half the maximum power for a sinusoidal alternating current.

Represent an alternating current or an alternating voltage by an equation of the form

*x*=*x*_{o}sin*w**t*.Distinguish between r.m.s. and peak values and recall and solve problems using the relationship

*I*_{rms}*= I*for the sinusoidal case._{o}/ sqrt(2)Show an understanding of the principle of operation of a simple iron-cored transformer and recall and solve problems using

*N*for an ideal transformer._{s}/ N_{p}= V_{s}/ V_{p}= I_{p}/ I_{s}Explain the use of a single diode for the half-wave rectification of an alternating current.