Question

A circuit with a battery, a 3 Ω resistor, a 21 Ω resistor, and a 21 Ω resistor in parallel. The total voltage is the system is 1.0 V. What is the total resistance of the circuit?

Answer 1

ANSWER:

7/3 Ω

STEP-BY-STEP EXPLANATION:

We have that as it is a parallel circuit, the total resistance is calculated as follows:

$\frac{1}{R_t}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}_{}_{}$

Replacing:

$\begin{gathered} \frac{1}{R_t}=\frac{1}{3}+\frac{1}{21}+\frac{1}{21} \\ \frac{1}{R_t}=\frac{7}{21}+\frac{1}{21}+\frac{1}{21} \\ \frac{1}{R_t}=\frac{9}{21} \\ R_t=\frac{21}{9}=\frac{7}{3}\Omega \end{gathered}$

Total resistance is 7/3 Ω