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

7/3 Ω

Explanation:

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

`(1)/(R_t)=(1)/(R_1)+(1)/(R_2)+(1)/(R_3)_{}_{}`

Replacing:

`\begin{gathered} (1)/(R_t)=(1)/(3)+(1)/(21)+(1)/(21) \\ (1)/(R_t)=(7)/(21)+(1)/(21)+(1)/(21) \\ (1)/(R_t)=(9)/(21) \\ R_t=(21)/(9)=(7)/(3)\Omega \end{gathered}`

Total resistance is 7/3 Ω