Phase, [180]
Plate, of an audion, [41]
Plunger type of instrument, [205]
Polarity of a coil, [204]
Power, defined, [234];
electrical unit of, [235]
Proton, properties of, [4]
Radio current, modulation of, [145]
Radio-frequency amplification, [243];
limitations, [243]
Radio-frequency amplifier, [186], [198]
Radio station connected to land line, [254]