Question

Find the equivalent resistance between points A and B shown in the figure(Figure 1). Consider R1 = 1.9 Ω , R2 = 2.5 Ω , R3 = 4.4 Ω , R4 = 3.5 Ω , R5 = 5.5 Ω , and R6 = 7.1 Ω .

Answer 1

The equivalent resistance between the point A and B is 0.95 ohm.

Explanation:

Solving for R3, R4, and R5 since they are in parallel formation. Their equivalent resistance could be

                            1 / R = (1 /R3) + (1 / R4) + (1 / R5)

                                    = (1 / 4.4) + (1 / 3.5) + (1 / 5.5)

                            1 / R = 0.69

                                 R = 1.43 ohm.

Next solving R6 and leg of this resistance which are in series connection,

                                  r = R + R6

                                    = 1.43 + 7.1)

                                  r = 8.53 ohm.

Finally the three resistance R1, R2 and the leg resistance which are in parallel connection,

                              1 / r = (1 / 1.9) + (1 / 2.5) + (1 / 8.53)

                                     = 1.04 ohm

Equivalent resistance R eq = 1 / 1.04 = 0.95 ohm.