QuestionQuestionConceptConceptDocumentDocument

21. Alternating currents

Start with Concept to understand a topic, then use Question Bank to check what you know.

2 topics · 8 learning objectives

Your progress

Sign in to see your mastery and mistakes.

  1. 21.1 Characteristics of alternating currents

    1. 21.1.1The terms period, frequency and peak value as applied to an alternating

      • understand and use the terms period, frequency and peak value as applied to an alternating current or voltage

    2. 21.1.2Equations of the form x = x0 sin ωt representing a sinusoidally alternating

      • use equations of the form x = x0 sin ωt representing a sinusoidally alternating current or voltage

    3. 21.1.3The fact that the mean power in a resistive load is half the maximum power

      • recall and use the fact that the mean power in a resistive load is half the maximum power for a sinusoidal alternating current

    4. 21.1.4Root-mean-square (r.m.s.) and peak values and recall and use I r.m.s. = I0 /

      • distinguish between root-mean-square (r.m.s.) and peak values and recall and use I r.m.s. = I0 / sqrt(2) and Vr.m.s. = V0 / sqrt(2) for a sinusoidal alternating current

  2. 21.2 Rectification and smoothing

    1. • distinguish graphically between half-wave and full-wave rectification

    2. • explain the use of a single diode for the half-wave rectification of an alternating current

    3. • explain the use of four diodes (bridge rectifier) for the full-wave rectification of an alternating current

    4. • analyse the effect of a single capacitor in smoothing, including the effect of the values of capacitance and the load resistance