A current flowing through you of more than 5 ma is considered dangerous. Why do
ID: 1502551 • Letter: A
Question
A current flowing through you of more than 5 ma is considered dangerous. Why do we see warnings about high voltage, rather than high current? What voltages are dangerous even if the skin is dry? (Dry skin has a resistance of 100 kohms while wet skin can be much less.) An electroencephalogram (EEG) is a recording of differences in voltage observed on the scalp by attaching electrical contacts. If voltage differences that are observed are about 0.5 mv, and the resistance of the skin is about 10 kohms, what size currents are involved?
Explanation / Answer
Why do we see warnings about high voltage, rather than high current?
Because of the voltaje is the potential or the engine that allow move to electrons, if not exist enough voltage the electrons not can run through you.
What voltages are dangerous even if the skin is dry? (Dry skin has a resistance of 100 kohms while wet skin can be much less.)
If the resistence of the skin is 100kohms you can stimate the voltaje minimum that is considered dangerous, for example if you take the 5mA of point above, V= IR, then:
5mA*100Kohms= V = 5*10-3 *100*103 = 500 Volts.
An electroencephalogram (EEG) is a recording of differences in voltage observed on the scalp by attaching electrical contacts. If voltage differences that are observed are about 0.5 mv, and the resistance of the skin is about 10 kohms, what size currents are involved?
You need to calulate the current I = V/R =0.5mV/10kohm = 0.5*10-3 / 10*103 = 5*10-8 A