Watt, [235]

Wave form, [182]

Wave length, relation to frequency, [98], [122];
defined, [122]

Wire, inductance of, [104]

Wire, movement of electrons in, [14];
emission of electrons from, [37]

Wire telephony, [253]

Wired wireless, [255];
advantages of, [257]

X-rays, [147]

Zero coupling, [177]

Zinc, electrode for battery, [23]