Electricity 2 — AC Circuits
RMS voltage, reactance, series RLC impedance, and resonance — with the impedance dip plotted live.
DC was a steady push. AC alternates — the voltage swings up and down like a sine wave, 60 times a second. Two components that did almost nothing in DC now come alive: inductors and capacitors, which resist change rather than steady current. Their tug-of-war produces resonance — the effect behind every radio tuner.
- 01 Peak vs RMS ELI5: the "120 V" on the wall is not the peak the voltage actually reaches — it's the RMS value, the equivalent steady DC voltage that would heat…
- 02 Reactance — resistance that depends on frequency ELI5: an inductor hates changing current — the faster the change, the harder it pushes back, so its reactance X_L = 2π·f·L rises with frequency. A capacitor is…
- 03 Series RLC — impedance ELI5: put R, L, and C in series and the two reactances fight — X_L pushes the voltage one way in time, X_C the other. What the source actually feels is the…
- 04 Resonance ELI5: sweep the frequency and there's exactly one spot where X_L = X_C — they cancel, impedance collapses to just R, and current spikes. That special…
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