War of Currents – Ward Leonard control – Watt – Wattmeter – Waveguide (electromagnetism) – Waveguide – Weber – Welding – Wet Transformer – Whitaker Foundation – Whole-life cost – Wiener filter – Wiener process – Williams tube – Wind farm – Wind power in South Australia – Wind power – Wind speed – Wind turbine – Wire – Wireless network – Wireless telegraphy –