• summary_type: concept
• word_count: 160

Alternating current varies sinusoidally: V(t) = V_0 sin(omegat). The peak value V_0 is the maximum instantaneous voltage. The RMS value V_rms = V_0/sqrt(2) is the effective value — an AC source of V_rms delivers the same power to a resistor as V_rms of DC. The mean value over a full cycle is zero; over a half cycle it is 2V_0/pi. Indian household supply: V_rms = 220 V, V_0 = 311 V, f = 50 Hz, omega = 100pi rad/s. For a square wave of amplitude V_0, V_rms = V_0 (since V^2 is constant). For a triangular wave, V_rms = V_0/sqrt(3). These relationships are derived from V_rms = sqrt((1/T)*integral of V^2 dt). JEE frequently tests conversions between peak, RMS, and mean values, especially comparing power delivered by different waveforms through the same resistor.