Question

A DC current of 60 mA can cause paralysis of the body's respiratory muscles and hence interfere with breathing, but only 15 mA (rms) of AC current will do the same thing. Suppose a person is working with electrical power lines on a warm humid day and therefore has a low body resistance of 1100 OHMS. What DC and AC (amplitude and rms) potentials would it take to cause respiratory paralysis?

Answer 1

To solve this problem it is necessary to apply the concepts related to Ohm's Law to find the voltage in the case of direct current. While for the Alternate current we use the concept of RMS voltage.

PART A) In the case of DC we have to,

V=IR

Where,

I = Current

R = Resistance

Where the current is 60mA y the resistance is $1000\Omega$ , then the potential would be

$V=(60mA)(1100\Omega)$

$V = 66V$

In the case of DC we have that the current and the RMS voltage is,

$I_{rms} = 15 mA$

$R = 1100 \Omega$

$V_{rms} = 16.5 V$

The potential in AC then is,

$V_o = \sqrt{2}V_{rms}$

$V_o = \sqrt{2}(16.5)$

$V_o = 23.3345 V$