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 1400 Ω . What dc V dc and what ac (amplitude V 0 and rms V rms ) potentials would it take to cause respiratory paralysis?

Answer 1

Step-by-step explanation:

d c current that can cause paralysis

= 60 x 10⁻³ A.

If body resistance = 1400 ohm

d c voltage that can generate the current above

= resistance x current

= 1400 x 60 x 10⁻³

= 84 V .

a c current ( rms ) that can cause paralysis

= 15 x 10⁻³ A.

a c voltage (rms ) that can generate the current above

= resistance x current

= 1400 x 15 x 10⁻³

Vrms = 21 V

maximum amplitude of ac voltage

= √2 x 21

= 29.7 V