Three 20Ohm resistors are connected across the sides of an e

Three 2.0-Ohm resistors are connected across the sides of an equilateral triangle ABC as shown in Figure 21-7. What is the equivalent resistance between any two points, AB, BC, or AC. of this circuit? 2.0 Ohm 1.3 Ohm 3.3 Ohm 4.3 Ohm 6.0 Ohm

Solution

Consider the equivalent resistance across AB. Then, the resistance across AC and BC are in series whose total resistance is in parallel with AB.

AB + BC = 2 + 2 = 4

R_eq = 2*4/(2+4) = 1.3 ohm

Answer is B.