___average___power.

RMS voltage and current are, however, entirely meaningful. If you compare half- and full-wave

___voltage_,__you will find the rms voltage of the half wave to approx .707 times the rms voltage of the full wave. With a resistor load, Power=(voltage squared)/resistance thus when you square .707 (actually 1/SQRT(2)), you get 1/2 so the half wave rectified wave delivers exactly half the power to the load.

Ted