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AC Waveform & Power Explorer

Explore sinusoidal timing, r.m.s. conversion, resistive power and ideal half-wave output with synchronized graphs and exam checkpoints.

  • GCE A-Level H2 Physics 2027
Learning goals
  • Represent sinusoidal a.c. and use peak and r.m.s. values.
  • Analyse mean power in resistive a.c. loads and half-wave rectification.

Interactive stageLive model

Loading the interactive model…The interactive model did not load. Try again reloads this page; the explanation and worked content here are still available.

Change one variable at a time and watch the model respond.

Waveform setup

Model and values
12 V
50 Hz
90°
Learning options
Guidance

AC checkpoint

Explore the model, then start a prediction.

What to notice:

    Practice run

    Choose a mode and checkpoint count when you want scoring.

    Run mode
    Try Structured Current Practice

    Choose your checkpoint count for guided or challenge mode.

    Study lensRelate period, frequency, angular frequency and phase on a sinusoidal waveform.11 min activity

    Try this

    Name the waveform and value type before choosing an equation.

    Learn to

    • Relate period, frequency, angular frequency and phase on a sinusoidal waveform.
    • Convert sinusoidal peak values to r.m.s. values and calculate mean power in a resistor.
    • Explain why resistive instantaneous power is non-negative and repeats at twice the supply frequency.

    Exam transfer

    • Sinusoidal a.c.
    • r.m.s. and power
    • Half-wave rectification

    Governing idea

    For a sinusoid, T = 1/f, ω = 2πf and Vᵣₘₛ = V₀/√2. In a resistor, p = vi = V₀I₀ sin²(ωt) and mean power is Vᵣₘₛ²/R.

    Model boundary

    The r.m.s. shortcut V₀/√2 and the mean-power shortcut ½V₀I₀ apply to complete sinusoids. Rectification uses an ideal diode unless a forward drop is stated.

    Avoid this trap

    The ordinary mean of a sinusoid is zero, but its r.m.s. value is not. Half-wave output is unidirectional pulsating d.c., not a smaller complete sinusoid or steady d.c.

    How to explore

    Read synchronized a.c. graphs and decide whether a question needs peak, r.m.s., instantaneous or rectified values.

    Predict the outcome, change one variable at a time, then interpret the result. Completion records participation only and does not award mastery.

    About this activity

    Explore sinusoidal timing, r.m.s. conversion, resistive power and ideal half-wave output with synchronized graphs and exam checkpoints. A text explanation and no-JavaScript route remain available.

    How this activity affects progress
    Course and syllabus information
    Course
    GCE A-Level H2 Physics
    Edition
    GCE A-Level H2 Physics 2027