Chapter 1, Problem 1RQ

In a work situation where an electrician’s hands get wet while operating a 120-volt, corded drill, which of the following would be true? (Objective 1-1)
a. Body resistance increases, and any shock would be mild.
b. Body resistance remains the same, and there is no danger as Long as rubber boots are worn.
c. Body resistance is substantially decreased, and severe shock could occur.
d. There is no danger as Long as a three-prong plug is used.

To determine

The true statement for the situation where an electrician’s hands get wet while operating a $120\text{Volts}$ corded drill.

Answer to Problem 1RQ

Option (c) Body resistance is substantially decreased, and severe shock could occur.

Explanation of Solution

Introduction:

According to the Ohm’s law, the relation between the current, voltage, and resistance is given by,

  $\text{Current}=\frac{\text{Voltage}}{\text{Resistance}}$

Here, the current is in amperes, voltage is in volts, and resistance is measured in Ohm’s.

The flow of current through any material depends upon the resistance provided by the material. The higher is the circuit resistance, the lower the current flow that a voltage can push through the circuit and vice-versa.

Dry skin offers much more resistance in comparison to the wet body. This means that higher the resistance value, the more opposition to the current flow through the body.

The following table shows the value of resistance with respect to the different conditions:

Skin Condition	Resistance
Dry skin	$100,000$ to $500,000\text{ohms}$
Sweaty hands	$1000\text{ohms}$
In water	$150\text{ohms}$

As shown in the above table, the value of resistance for wet hands is very less so if in a work situation where an electrician’s hands get wet while operating a $120\text{Volts}$ corded drill, then body resistance is substantially decreased, and severe shock could occur. Thus, the option (c) is correct.

As shown in the above table, the value of resistance for wet hands is very less, so the shock will not be mild. Thus, option (a) is incorrect.

Therefore, the body resistance will not remain the same if the hand gets wet. Thus, option (b) is incorrect.

The electrician will always be in danger if his hands are wet. Thus, option (d) is incorrect.

Conclusion:

Therefore, the Option (c) Body resistance is substantially decreased, and severe shock could occur is best suitable answer for the given statement.