Three resistances, P, Q, R each of 2 and an unknown resistance S form the four arms of a Wheatstone bridge circuit. When a resistance of 6 is connected in parallel to S the bridge gets balanced. What is the value of S?
- 3
- 6
- 1
- 2
Answer
(1) 3
Solution
Balanced Wheatstone bridge: PQ = RS', where S' = S in parallel with 6 .
22 = 2S'
S' = 2
6S6 + S = 2
6S = 12 + 2S
S = 3
Answer: (1)