## What makes alternating current alternate?

#### What makes alternating current alternate?

The pump for alternating current (usually an electrical generator) creates electric fields that reverse their directions 120 times a second (60 full cycles of reversal, over and back, each second). This reversal pushes the current backward and forward through the wires connecting to this power source. The currents direction of flow alternates and so does its voltage.

## Is it true that if you double the current through a wire then you double the vol…

#### Is it true that if you double the current through a wire then you double the voltage loss and if you halve the current then you halve the voltage loss?

Yes. When you try to push current through a wire, the voltage drop across that wire (i.e. the energy lost by each charge passing through that wire) is proportional to the number of charges flowing through that wire each second (i.e. the current through the wire). If you double the number of charges flowing through the wire each second, then each charge will lose twice as much energy (the voltage drop across the wire will double). If you halve the number of charges flowing through the wire each second, then each charge will lose half as much energy (the voltage drop across the wire will halve).

## When going from 12 volts to 240 volts, is the point that with higher voltage the…

#### When going from 12 volts to 240 volts, is the point that with higher voltage the power transfer proceeds with fewer particles?

Yes. If you use higher voltages, you can transfer the same amount of power with a small current of charged particles. The energy lost in the transmission through wires increases as the square of the amount of current through those wires so reducing that current is very important.