Question

A circuit is built based on this circuit diagram. What is the equivalent resistance of the circuit?

Answer 1

The three resistors are connected to the same points of the circuit, so they are in parallel configuration. The equivalent resistance of 3 resistors in parallel is given by:
$\frac{1}{R_{eq}}= \frac{1}{R_1}+ \frac{1}{R_2}+ \frac{1}{R_3}$
If we plug the values of the resistances into the formula, we find
$\frac{1}{R_{eq}}= \frac{1}{3.0 \Omega}+ \frac{1}{6.0 \Omega}+ \frac{1}{9.0 \Omega}= \frac{6+3+2}{18.0 \Omega} = \frac{11}{18.0 \Omega}$
From which we find the equivalent resistance:
$R_{eq} = \frac{18.0}{11} \Omega =1.6 \Omega$

So, the correct answer is B.