Question

A human being can be electrocuted if a current as small as 55 mA passes near the heart. An electrician working with sweaty hands makes good contact with the two conductors he is holding. If his resistance is 2300 Ω, what might the fatal voltage in volts be?

Answer 1

Answer:

126.5 V

Explanation:

Using Ohm's Law,

V = IR............................. Equation 1

Where V = Voltage, I = current, R = resistance.

Note: The current needed to bring about the fatal voltage is equal to the current that will cause human being to be electrocuted.

Given: I = 55 mA = 55/1000 = 0.055 A, R = 2300 Ω

Substitute into equation 1

V = 0.055×2300

V = 126.5 V.

Hence the fatal voltage = 126.5 V

Answer 2

Answer:

The lethal voltage for the electrician under those conditions is 126.5 V.

Explanation:

To discover what is the lethal voltage to the electrician we need to find out what is the voltage that produces 55 mA = 0.055 A when across a resistance of 2300 Ohms (Electrician's body resistancy). For that we'll use Ohm's Law wich is expressed by the following equation:

V = i*R

Where V is the voltage we want to find out, i is the current wich is lethal to the electrician and R is his body resistance. By applying the given values we have:

V = 0.055*2300 = 126.5 V.

The lethal voltage for the electrician under those conditions is 126.5 V.