Alternating currents – Physics Academy London

CAIE
21. Alternating currents

understand and use the terms period, frequency and peak value as applied to an alternating current or voltage
use equations of the form x = x0 sin ωt representing a sinusoidally alternating current or voltage
recall and use the fact that the mean power in a resistive load is half the maximum power for a sinusoidal alternating current
distinguish between root-mean-square (r.m.s.) and peak values and recall and use I r.m.s. = I0 / 2 and Vr.m.s. = V0 / 2 for a sinusoidal alternating current

distinguish graphically between half-wave and full-wave rectification
explain the use of a single diode for the half-wave rectification of an alternating current
explain the use of four diodes (bridge rectifier) for the full-wave rectification of an alternating current
analyse the effect of a single capacitor in smoothing, including the effect of the values of capacitance and the load resistance