A 2.0-Ω resistor is in series with a parallel combination of 4.0-Ω,6.0-Ω,and 12-Ω resistors.What is the equivalent resistance of this system?
A)24 Ω
B)4.0 Ω
C)1.8 Ω
D)2.7 Ω

Question

Quizplus · Accepted Answer

The equivalent resistance of the parallel combination is found using the formula 1/R_eq = 1/R_1 + 1/R_2 + 1/R_3. For the 4.0-Ω, 6.0-Ω, and 12-Ω resistors, this gives 1/R_eq = 1/4 + 1/6 + 1/12 = 1/2, so R_eq = 2 Ω. Adding this to the series 2.0-Ω resistor gives a total equivalent resistance of 4.0 Ω.

A 20-Ω Resistor Is in Series with a Parallel Combination of of 4.0-Ω,6.0-Ω,And