Chapter 10, Problem 4TS

Rearrange the equation current = voltage/resistance to express resistance in terms of current and voltage. Then consider the following: A certain device in a $120\text{ V}$ circuit has a current rating of $20\text{ A}$ . show that the resistance of the device is $6\Omega$ .

Solution

To determine: The resistance.

Answer:

The resistance is $6\Omega$ .

Explanation:

Given info: The current is $20\text{A}$ and the voltage is $120\text{V}$ .

According to Ohm’s law, write the expression for current.

$\begin{array}{l}V=IR\\ R=\frac{V}{I}\end{array}$

Here,

$V$ is the voltage

$R$ is the resistance

Substitute $20\text{A}$ for $I$ and $120\text{V}$ for $V$ in the above expression to get $R$ .

$\begin{array}{c}R=\frac{120\text{V}}{20\text{A}}\\ =6\Omega \end{array}$

Conclusion:

Therefore, the resistance is $6\Omega$ .