Question

A circuit is built based on this circuit diagram.

A diagram of a closed circuit with a power source on the left labeled 12 V. There are 3 resistors in parallel, separate paths, connected to it labeled 3.0 Ohms, 6.0 Ohms and 9.0 Ohms.
What is the equivalent resistance of the circuit?

0.61 Ω
1.6 Ω
7.5 Ω
18 Ω

Answer 1

Use 1/Req = 1/3 + 1/6 + 1/9 = (6+3+2)/18 = 11/18, so Req = 18/11 ≈ 1.636 Ω. Rounded to two sig figs (matching the given values) gives 1.6 Ω.