Question

Long-distance, electric-power, transmission lines always operate at very high voltage, sometimes as much as 750 kV. What are the advantages of such high voltages? What are the disadvantages?

Short answer

The advantage is for the high voltage, the current will be small so the heat losses are very small.

And the disadvantages are it is dangerous to get close to a transmission line and another disadvantage is that we need to step up and step down at receiving and transmitting stations.

Step-by-step solution

Power consumption of the electric circuit

Power (P) in an electric circuit is exactly equal to current (I) multiplied by voltage (E)

Determine the advantages and disadvantages of high voltage

For the high voltage, the current will be small so the heat losses are very small.

The disadvantages are it is dangerous to get close of a transmission line and another disadvantage is that we need step up and step down at receiving and transmitting stations.

Therefore, the advantage is for the high voltage, the current will be small so the heat losses are very small.

And the disadvantages are it is dangerous to get close to a transmission line and another disadvantage is that we need to step up and step down at receiving and transmitting stations.