PHYS345 PHYS345 Class 11

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  Concept Check: Thinking with Phasors

Warning! Electrical Safety
This is presented as a public service. Please inform me if you find any errors...

Ouch! CURRENT KILLS (not voltage)

Current effects on human body, current through chest
(A, amps)
<0.01   tingling or imperceptible
0.02   painful, cannot let go
0.03   breathing disturbed
0.07   breathing very difficult
0.10   death due to fibrillation
>0.20   no fibrillation, but severe burning, no breathing
Also please see Electrical Hazards from the MIT Safety Office

Effects of different current levels through human body

Fibrillation and resuscitation
[heart signal]
  • Fibrillation is the fine, rapid, erratic, movements that replace the normal contraction of the vetricular muscle of the heart
  • Fibrillation can be stopped by application of another controlled electrical shock, known as defibrillation, often seen in movies and on TV...
  • A stopped heart can often be resuscitated with CPR techniques (cardiopulmonary resuscitation), but seldom a fibrillating heart.

Dielectric breakdown and sparking

[High Voltage]
graphic from City of Austin Electric Utility
Electrical Safety from the MIT Safety Office
Using Electricity Safely from Ohio Edison
Safety Search (for children) from Union Electric

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Last updated October 3, 1998.
Copyright George Watson, Univ. of Delaware, 1998.