Why is mains electricity AC (Alternative current)?

Question

Why is mains electricity AC (Alternative current)?

Answer 1

AC voltage can be transformed, using a transfromer from high voltage to lower voltage. When you do that, you also get proportionally more current.

This means that you can transmit electricity long distances over long wire at high voltage and low current. Since it is current flow that causes power loss in a resistive conductor (I squared R loss) and wires are a bit resistive...especially over miles and miles of wire...it is preferable to transmit power at the lowest current possible.

So, since DC Voltage cant be easily transformed.....or at least couldn't back in the day....power transmission via high voltage AC won out....

Answer 2

Mains Electricity

Answer 3

Get a dipstick heater. They take about 90w of energy to run, but most are 110v units. But this is an easy solution - like you mentioned, you can get a spare battery and then use a small wattage inverter to power it. A fully charged battery should be able to handle a 90 watt drain for a couple of hours. Put a mountable charger on the battery, so when you get home all you have to do is plug it in, rather than connect/disconnect the charging terminals. If you are close enough to the car from where you work, you could always install a remote starter for your car. Then, you don't have to run out to start it - you can turn the car on/off remotely. And as the other post mentioned - if you worry that much about the battery, turning the lights on a little bit will warm the battery. As for coolant - ensure that you have the appropriate ratio for the expected temperature, and that shouldn't be a problem.

Answer 4

There is a power loss accociated with the transmission. This is E^2/R where E is the voltage and R is the resistance of the transmission wires. (This resistance is in series with the load and hence a power loss.
AC voltage can be stepped up or down with transformers.
The AC voltage is stepped up at the power source and transmitted a long distance, then stepped down at the load end to useful level. An equivelent circuit would show the transmission lines as resistance. Draw this out, then do the math to see the difference in power losses!
If we were allowed to put drawings and stuff in this box I could show you with much greater clarity. (But Noooooo!!!!)
The answer is simply due to efficiency.

Answer 5

Because it is easy to transform AC from high voltage to low. High voltage means that more power can flow through the wires with less current, therefore less heat losses. So transmission is done at 40,000 volts or higher and it is reduced at distribution centers to 4800 then down further at transformers on poles to business or household needs.
Direct Current is actually more efficient at any given voltage because there are no peaks to cope with, but until recently with solid state convertors, the only way to change voltage was to drive a motor with the high voltage DC and run a generator that produced lower voltage DC with all the motor and generator losses.

Answer 6

Electricity goes on from negative unto the positive region, neutrino without with no aids either, exit or simply just quit,
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Answer 7

It can be stepped up or stepped down to any voltage we like using a transformer.