A 10- $\Omega$ resistor is connected in parallel with a 30- $\Omega$resistor. The total resistance of the combination is
A) 7.5 $\Omega$
B) 15 $\Omega$.
C) 40 $\Omega$.
D) 300 $\Omega$

Question

A 10- $\Omega$ resistor is connected in parallel with a 30- $\Omega$resistor. The total resistance of the combination is
A) 7.5  $\Omega$
B) 15  $\Omega$.
C) 40  $\Omega$.
D) 300  $\Omega$

Quizplus · Accepted Answer

The total resistance $R_{total}$ for resistors in parallel is given by $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2}$. For a 10-ohm and a 30-ohm resistor in parallel, $\frac{1}{R_{total}} = \frac{1}{10} + \frac{1}{30} = \frac{3}{30} + \frac{1}{30} = \frac{4}{30} = \frac{1}{7.5}$, so $R_{total} = 7.5$ ohms.

A 10- Ω\OmegaΩ Resistor Is Connected in Parallel with a 30- Ω\OmegaΩ

A 10- $\Omega$ Resistor Is Connected in Parallel with a 30- $\Omega$