Question

Four resistors of 2.0Ω each are joined end to end to form a square ABCD. Calculate the equivalent resistance of the combination between any two adjacent corners.
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Answer 1

Let us consider the equivalent resistance between points A and B. Here, three resistances of 2 ohm each are in series, and this combination is connected in parallel across the resistor of 2 ohm(AB) (R2 = 2 ohm)

Equivalent resistance of the three series resistors = R1= 2 + 2 + 2 = 6 ohms

Thus, required equivalent resistance (R)

1/R = 1/R1 + 1/R2

= 1/6 + 1/2 = 4/6

R = 1.5 ohm.