One that's always puzzled me... three pins in a plug, the earth, the live and the neutral. The live is the fused one and even sounds like it's going to hurt you, but the neutral one doesn't have a fuse - does that mean you wouldn't get a shock if you touched the neutral wire? Here's the real puzzler - as mains is Alternating Current shouldn't the neutral be just as hazardous as the live?
2006-12-01 10:53:57 · 11 answers · asked by go_on_tell_us 1 in Science & Mathematics ➔ Physics
The neutral pin is connected to earth and therefore it is at zero potential in general.
But due to various reasons, it is not necessary that it should always at zero potential.
Therefore, it is always safe if we avoid touching the neutral pin also.
But I hope you are puzzled, “Why the neutral pin is not as active as the live pin while the supply is an alternating one?”
The answer is simple. It is because the neutral wire is connected to earth.
And the earth always remains at zero potential.
Therefore the neutral pin will always remain at zero potential.
Suppose the supply is 250 V at 50 cycles per second. This means that the maximum voltage is 354 V.
The neutral pin is always at zero potential where as the potential of the live pin with respect to the neutral pin will oscillate between +354 V to zero to -354V to zero and again to +354V in 0.02 second.
If the neutral pin is not connected to earth then both pin will have the potentials oscillating between the ranges shown with respect to earth.
2006-12-01 22:11:59 · answer #1 · answered by Pearlsawme 7 · 0⤊ 1⤋
Although the neutral is earthed at some point, when it is carrying a current, the resistance of the neutral wire means that it will normally be a few volts above earth potential.
However, under fault conditions, for example if the earth terminal has become disconnected, or if the neutral has a high-resistance (ie bad connection) somewhere or there is a faulty appliance on the circuit, it could get to line voltage (240 volts in UK).
You should always assume that the neutral could be carrying mains potential.
The alternating current means that the live connection goes alternatively positive and negative relative to earth potential.
Therefore, 100 times a second it is actually at earth potential, but I wouldn't like to risk touching it at that instant.
2006-12-02 06:46:11 · answer #2 · answered by Up the pole 2 · 0⤊ 1⤋
The hot wire (black - fused), as you state in your question, is the one that is 120 volts AC live to ground. The path to ground for this wire is the neutral wire - which is tied to ground in the service panel. The actual ground wire, when present, is for safety concerns only is not part of the actual circuit as far as current flow is concerned.
With this in mind, it would seem that the neutral wire would be safe since it is tied to the same connection as the ground wire back at the service panel. DON'T BELIEVE IT.
Remember, the neutral is the return path to ground. If there were an appliance plugged into the same circuit which completes the circuit from the hot wire to the neutral wire - the neutral wire that is disconnected from its return path is now 120 volts live to ground! If you touch it, you may well become the ground path that the appliance is looking for - OUCH !
Always cut the power and recheck it before attempting any repairs - and, you do not have to touch two wires to get a shock, one wire will do just fine.
2006-12-01 20:41:50 · answer #3 · answered by LeAnne 7 · 0⤊ 1⤋
The thing to remember is that electricity will always follow the easiest path or path with least resistence. The hot wire delivers electrons to the load (light, computer, appliance, etc.). Excess electrons will flow back to a neutral reference. IF you theoretically cut the neutral wire and held one side in each hand, you would surely get shocked. However, if you scraped the insulation off the neutral wire and held it in one hand, you may or may not get shocked. It would depend on the resistance of your body to reference ground as compared to the path back through the wire. If you stood on a metal ladder dripping wet from a shower and tried this, you would most likely get shocked because your resistance to ground might be less than the resistance of the neutral wire. However, if you were wearing rubber shoes standing on a wooden floor and not touching anything else you would most likely not get shocked as the resistance of the rubber and wood would be less than the resistance in the wire.
the ground wire is really a duplicate of the neutral wire in physical practice as they both terminate on the neutral bus in the fuse box. However, the ground is not expected to carry any electrons except in upset or overload conditions.
2006-12-01 19:11:00 · answer #4 · answered by MrWiz 4 · 0⤊ 1⤋
Theory is No. However if you have appliance plugged in to a socket close to you. You may get Back EMF (Electro Motive Force) if your body's earth is better than the House Earth. In practise the answer is usually No.
Power in AC is actually alternating between the Neutral and Live connection and not the Earth. An appliance can run happily without an earth connection, but could be Very dangerous if not double insulated!
2006-12-01 19:04:02 · answer #5 · answered by WavyD 4 · 0⤊ 1⤋
If you just stick your finger up the neutral hole in a socket, you should be fine, but if you touch the neutral side of a device as it's drawing current you'll get a shock, because you are in effect also connecting to the live (via the device).
2006-12-01 18:59:07 · answer #6 · answered by Anonymous · 0⤊ 0⤋
you got to touch 2 wires to get a shock
2006-12-01 19:06:50 · answer #7 · answered by Anonymous · 0⤊ 4⤋
yes if there is a unbalanced phase you get small voltage
2006-12-01 19:48:27 · answer #8 · answered by mikeburgess2006@yahoo.co.uk 1 · 0⤊ 1⤋
try and see
2006-12-01 18:55:53 · answer #9 · answered by mannit m 4 · 0⤊ 2⤋
no
2006-12-01 18:55:51 · answer #10 · answered by fair-and-squire 4 · 0⤊ 1⤋