The value of current I in the electrical circuit as given below, when potential at A is equal to the potential at B, will be A. [figure]
Answer
2
Solution
VA = VB balanced Wheatstone bridge, no current through 30
Balance condition: 1020 = R40 R = 20
Upper branch: 10 + 20 = 30 ; lower branch: 20 + 40 = 60
Equivalent resistance: Req = 30 6030 + 60 = 20
I = 4020 = 2 A
Answer: 2