3 ms·
V=IR only holds for direct current. The transmission lines can be run at high voltages and relatively small diameters because they carry alternating current, wh
by jschwartzi 11y ago
V=IR only holds for direct current. The transmission lines can be run at high voltages and relatively small diameters because they carry alternating current, which is a much more efficient way of transmitting electrical energy over long distances. If they were DC then they would be sized more like sewer pipes.
- upofadown 11y agoV=IR works perfectly well for AC just as long as you measure the AC in terms of RMS voltage and current. For sinusoidal AC the result is about 0.7 the peak value. There would be no significant difference in wire size. DC is in fact the better way to transmit energy over long distances. The computer I am typing this on is powered by energy transmitted 900 km in the form of DC.