Question

Find the current through a person and identify the likely effect on her if she touches a 120 V AC source in the following circumstances. (Note that currents above 10 mA lead to involuntarily muscle contraction.) (a) Find the current (in mA) if she is standing on a rubber mat and offers a total resistance of 325 kΩ.

Options:

A) 0.369 mA
B) 0.254 mA
C) 0.415 mA
D) 0.182 mA

Answer 1

The current through a person who touches a 120 V AC source while on a rubber mat with a resistance of 325 kΩ is 0.369 mA, which is below the threshold that could lead to involuntary muscle contraction.

Step-by-step explanation:

To calculate the current through a person who touches a 120 V AC source while standing on a rubber mat with a total resistance of 325 kΩ, we use Ohm's Law:

I = V/R

Where:

• I is the current
• V is the voltage (120 V)
• R is the resistance (325 kΩ or 325,000 Ω)

Plugging in the values we get:

I = 120 V / 325,000 Ω

I = 0.000369 A, which is equivalent to 0.369 mA

This current is below the involuntary muscle contraction threshold (10 mA), so the person might feel a tingling sensation but is unlikely to experience severe effects such as muscle contraction or a more serious condition.