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![[Post New]](/templates/default/images/icon_minipost_new.gif) 5 Apr 2008 19:57:37 IST
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Resistance of human body is about 10 kilo-ohm .If the resistance is such large then why does one experience a strong shock from a live wire of 220V supply??
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the shock experienced when one touches a live wire is attributed to several factors.......
firstly,the 220v value is only the rms value,the actual value is close to about 311v.....
any live wire has rapidly fluctuating current that moves from -311v to +311v in 1/60th of a second......the frequency is quite high.....
then,ac current is able to flow through the body surface only........instead of moving through the bulk......
then again,u will gt a shock only whn u r standing on d ground and touching d live wire,as d ground is an effective absorber of charge and is able to create a sufficiently high potential gradient.....
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"Many of the things you can count,dont count....
Many of the things you cant count,really do count...."-Albert Einstein
"The important thing in science is not so much to obtain new facts as to discover new ways of thinking about them"-William Bragg
"An inexplicable fact is infinitely preferable to an incomprehensible mystery"-F. Soddy
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5 Apr 2008 20:15:26 IST
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When body comes in contact with live wire its potential becomes 0,therefore current flows thro us 2 earth however resistance of the body just obstructs its path but due to flowing current it gets a severe shock
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5 Apr 2008 20:18:03 IST
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@kapil i didnt get it..........
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5 Apr 2008 20:18:24 IST
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well i have an interesting fact for u....if a man comes in contact with live wire and is on the ground he ll surely get electrocuted.....thts bcause there exists potential diff...but if a man just hangs from a live wire and doesnt touch any object at a lower potential ..he ll merely be swinging there......thts bcause his potential will be adjusted to the pot of the live wire and as there is no pot diff..the current also will not pass through himm....hope u liked it...rate if useful..
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5 Apr 2008 20:21:48 IST
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bur such a high resistance and small pd of 220??
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5 Apr 2008 20:30:10 IST
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the potential gradient is also high enough....
imagine,in 1/60th of a second,voltage diff is nearly 311v....sum it ovr a second and u gt a massive current...
then again,ac current flows thru surface and nt bulk,so resistance is rel less.....
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"Many of the things you can count,dont count....
Many of the things you cant count,really do count...."-Albert Einstein
"The important thing in science is not so much to obtain new facts as to discover new ways of thinking about them"-William Bragg
"An inexplicable fact is infinitely preferable to an incomprehensible mystery"-F. Soddy
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5 Apr 2008 23:11:20 IST
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The shock one feels depends on the combined effect of voltage and current,
that is to say the power which is the product of voltage and current.
The power = VI or V^2/r or I^2R.
The average resistance on human bodies being known it is usual to speak of the minimum current needed to get a shock. As already mentioned one can say in terms of voltage too.
rate if useful...........
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6 Apr 2008 06:20:39 IST
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how does power cause the shock???
i didnt get it............
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