Three resistances P, Q, R each of 2Ω and an unknown resistance S form the four arms of a Wheatstone bridge circuit. When a resistance of 6Ω is connected in parallel to S the bridge gets balanced. What is the value of S?

Question

Dr. Abubacker · Accepted Answer

[Solution from source] Balance requires P/Q = R/S', so the effective arm S' = 2 Ω. S in parallel with 6 Ω: 6S/(S + 6) = 2 gives 4S = 12, so S = 3 Ω. Answering 2 Ω forgets that S is in parallel with the 6 Ω. Answer (1).

Q. Three resistances P, Q, R each of 2Ω and an unknown resistance S form the four arms of a Wheatstone bridge circuit. When a resistance of 6Ω is connected in parallel to S the bridge gets balanced. What is the value of S?

Explanation

Reviewed by Dr. Abubacker

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