Why are electrical cords three pronged?

Answer 1

The ground pin is longer so it will make electrical contact first. This causes the device gets grounded before it gets power

Additional Answer

In the case of UK electrical plugs, it also has the function of opening the socket's safety shutters in order to allow the line/neutral pins to enter the socket.

Answer 2

Canada and US wiring - To maintain the polarity of the neutral to the fixture. On a 15 amp receptacle the neutral is on the left side. Whenplugging a lamp fixture into the receptacle it can only go in the slots one way. This keeps the neutral to the shell of the lamp holder socket and the hot side of the cord to the center pin in the bottom of the lamp holder socket. By using this configuration a person won't get a shock if the shell of the lamp holder accidentally gets touched.

Answer 3

Answer for USA, Canada and countries running a 60 Hertz supply service.It is used to get the correct polarity. On a two blade plug with no ground wire it is preferred to place the neutral wire into the correct receptacle hole. If you look at the receptacle there are two size holes, a larger one on the left and a smaller hole on the right. This configuration is if the receptacle is installed with the U ground pin on the bottom. The larger blade hole is for the neutral wire and the smaller hole is for the "hot" wire.

Answer 4

To complete a circuit, which means that electricity runs through one prong, through the appliance, and out the other.

Answer 5

Due to the fact that it needs to be grounded in-case there is a short in the energy flow so no one gets electrocuted.

Answer 6

One is hot, one is neutral. To severely oversimplify it current flows from one, through your load, and back into the other. Electricity always flows in loops.

Answer 7

Some devices are polarity-specific - this design prevents reverse polarity from being applied to those devices.