Will this man get an electric shock

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Discussion Overview

The discussion revolves around the conditions under which a properly insulated man might receive an electric shock when touching the terminals of two isolated 120 V batteries. Participants explore various scenarios, including grounding of battery terminals and the implications of voltage definitions.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants suggest that if a properly insulated man touches the positive terminal of one 120 V battery and the negative terminal of another isolated 120 V battery, he will not receive an electric shock due to the lack of a complete circuit.
  • Others argue that if the negative terminals of both batteries are grounded, the man could receive a shock if he is grounded himself; otherwise, he would not.
  • It is noted that grounding the positive terminals instead of the negative ones would present a similar risk, as the direction of current through the body does not affect the hazard.
  • One participant emphasizes that voltage should not be considered absolute, suggesting that the reference point for zero volts is arbitrary.
  • A personal anecdote is shared about experiences with 120 V batteries, indicating that shocks were not received unless significant contact was made, contrasting with a historical account of a severe shock from higher voltage batteries.
  • A theoretical perspective is introduced, stating that if the batteries are isolated, the individual should be safe unless there is significant capacitance present.

Areas of Agreement / Disagreement

Participants express differing views on the conditions under which a shock might occur, particularly regarding grounding and the interpretation of voltage. No consensus is reached on the overall safety of the scenarios presented.

Contextual Notes

Participants discuss the implications of grounding and the arbitrary nature of voltage reference points, but the discussion does not resolve the complexities involved in these electrical scenarios.

Frenemy90210
If a properly insulated man touches with one hand +ve terminal of a 120 V battery and with another hand -ve terminal of (Edit: an another) 120V battery (two batteries are totally isolated, not connected in any way) then will he get electrical shock ? ( I am guessing , not). But if -ve terminals of both batterys are properly grounded, say a mile apart, will he get shocked ?What if +ve instead of -ve terminals are grounded, what will happen ?

Edit: Man is not grounded and well insulated.
 
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Frenemy90210 said:
If a properly insulated man touches with one hand +ve terminal of a 120 V battery and with another hand -ve terminal of 120V battery (two batteries are totally isolated, not connected in any way) then will he get electrical shock ?

No. No circuit means no current.

Frenemy90210 said:
But if -ve terminals of both batterys are properly grounded, say a mile apart, will he get shocked ?

This presents essentially the same shock hazard as a single grounded battery. Is the man grounded in any way? If so then yes. If not then no. I would suggest against trying this yourself.

The distance between the ground is going to have little effect as long as the ground is "proper".

Frenemy90210 said:
What if +ve instead of -ve terminals are grounded, what will happen ?

This is the same as the previous situation. The direction of current though the body has no bearing on its hazard.

BoB
 
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Frenemy90210 said:
If a properly insulated man touches with one hand +ve terminal of a 120 V battery and with another hand -ve terminal of (Edit: an another) 120V battery (two batteries are totally isolated, not connected in any way) then will he get electrical shock ? ( I am guessing , not). But if -ve terminals of both batterys are properly grounded, say a mile apart, will he get shocked ?What if +ve instead of -ve terminals are grounded, what will happen ?

Edit: Man is not grounded and well insulated.

Stop thinking of voltages as abosolute. The absolute voltage of your 120V battery could be called 120000V or -1200V. The choice of zero volts is arbitrary.
 
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Incidentally, I used 120 volt batteries for my home made radio equipment when I was a boy and did not receive shocks from that voltage unless really trying and making very good contact.
On the other hand, John Logie Baird, when working on television development, was given a thousand volts-worth of batteries, which, imagining them to be safe, he touched, and received a horrendous shock that nearly killed him.
 
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In theory the two batteries are isolated so he should be ok as long as there isn't much capacitance around.
 

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