Question

why do electric utility companies increase the voltage of electricity for long - distance transmission? (check all that apply)check all that applythe current is reduced when the voltage is increased.energy loss is reduced by lowering the current.energy loss is reduced by stepping up the voltage.

Explanation:

• According to the formula \(P = UI\) (where \(P\) is power, \(U\) is voltage, and \(I\) is current), when the power \(P\) (the power to be transmitted) is constant, if \(U\) increases, \(I=\frac{P}{U}\) will decrease.
• The power loss in the transmission line is \(P_{loss}=I^{2}R\) (where \(R\) is the resistance of the transmission line). Since \(R\) is constant (determined by the material and length of the line), when \(I\) decreases (because \(U\) increases as \(P = UI\) is constant), \(P_{loss}\) decreases.

Answer:

• The current is reduced when the voltage is increased.
• Energy loss is reduced by lowering the current.