2006-08-24 03:32:52 · 9 answers · asked by gsm 1 in Science & Mathematics ➔ Engineering
Current will always try to pass through a circuit/path which has least resistance. Earth is the best conductor of electricity among all things therefor we ground the negative of the welding machine so that the current can flow directly to ground and not through our body. Our body has more resistance than ground/earth. Of course if you do not ground the negative terminal, you will be hit by the shock.
Similarly, buildings and tall structures have metal poles planted on their rooftops to absorb the lightning and pass it to ground. If you observe it closely, you will see a thick Aluminium/copper strip connected to the pole at one end and the other end is properly grounded.
2006-08-24 03:52:20 · answer #1 · answered by Inquisitive 1 · 1⤊ 1⤋
Jesus! Does anyone knows about OHM's law????
The Voltagfe is equal to the product of the current by the resistance, or V = R * I ???
When welding, the current flows from the source, through the cables, through the electrode, through the arc, through the peice, through the clamp and back to the source. The path of the current is of very low resistance (a few MILLIOHMS).
The welder has a small voltage output, but is capable of very high currents.
So, if the welder has 24V source, and the total resistance of the circuit is 0.1Ohms, the current is 240 Amperes.
Your body, on the other hand, has an average resistance of 1000 Ohms to 10,000 Ohms (depending on how "wet" you are!). So the current that COULD pass through you will never exceed
24 V / 1,000 Ohms = 0.024 Amps, barely enough to give you a shock.
Save for a car battery of 200 A/h! This can give 600 Amps to your starter motor, but will NEVER give you a shock.
Come on Guys, what's going on with you lot???
2006-08-24 05:01:43 · answer #2 · answered by just "JR" 7 · 1⤊ 0⤋
You are not in the circuit the welding circuit goes from one conductor to the other not through u to ground. It is not the current that shocks u it is the voltage. If the wire that connects to the pipe gets to ground and u touch the welding rod u could get a shock. To be dangerous u need enough voltage to push 100 to 200 mili amps through the chest from hand to hand. Less than 100 ma. no harm ,more than 200ma. can cause burns but will not cause the heart to fibulate.
2006-08-24 08:37:44 · answer #3 · answered by JOHNNIE B 7 · 0⤊ 0⤋
Because it's grounded to the object you are welding, thats what completes the circuit
2006-08-24 03:34:20 · answer #4 · answered by Anonymous · 0⤊ 1⤋
All the bl00dy time, especially Tesco trolleys. I dont know why. I get shocks sometimes when I touch my dog too, which makes him jump
2016-03-17 01:57:16 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Current takes the path of least resistance.....Don't be in the path!!
2006-08-24 06:26:49 · answer #6 · answered by Anonymous · 0⤊ 0⤋
We wear rubber gloves or rubber slippers which are bad conductors of heat. Anyways, isnt it good that v dont get shock. Why? u wanted one?
2006-08-28 02:14:22 · answer #7 · answered by Urvashi B 1 · 0⤊ 0⤋
because of lesser operating voltage. follow ohms law
voltage / current is equals to resistance.
2006-08-26 06:33:48 · answer #8 · answered by Anonymous · 0⤊ 0⤋
shock depend on how much current flow through us ,it depend upon
voltage, which is low
2006-08-24 23:25:05 · answer #9 · answered by kuldeep singh 1 · 0⤊ 0⤋
bcoz the conductor is grounded.current takes least path ie.,, thru ground not thru us
2006-08-24 19:29:44 · answer #10 · answered by pavan d 1 · 0⤊ 0⤋