Example from Physics, 19.2 Series Circuits

Calculation of Equivalent Resistance (part 1)

In the left circuit of the previous figure, suppose the voltage rating of the battery is 12 V, and the resistances are $R_{1} = 1.0 Ω, R_{2} = 6.0 Ω, and R_{3} = 13 Ω$ . (a) What is the equivalent resistance? (b) What is the current through the circuit?

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Strategy for (a)
Use the equation for the equivalent resistance of resistors connected in series. Because the circuit has three resistances, we only need to keep three terms, so it takes the form

$R_{equiv} = R_{1} + R_{2} + R_{3} .$
19.14
Solution
Solution for (a)

Inserting the given resistances into the equation above gives

$\begin{matrix} R_{equiv} & = & R_{1} + R_{2} + R_{3} \\ = & 1.0 Ω + 6.0 Ω + 13 Ω \\ = & 20 Ω. \end{matrix}$
19.15

0 of 2 steps open

How did it go?

Strategy for (a)

Solution

Strategy for (a)

Solution