The reading of the ammeter (A) in steady state in the following circuit (assuming negligible internal resistance of the ammeter) is A. [figure]
- 1/2
- 1
- 2
- 0
Answer
(2) 1
Solution
In steady state the capacitor branch (10 μF in series with 8 Ω) carries no current.
Let P be the junction after the 1 resistor. The ideal ammeter joins the lower ends of all the 8 resistors to the negative terminal of the cell.
Right part: the two right 8 resistors are in parallel = 4 , in series with 4 8 from P to the bottom wire.
This is in parallel with the left 8 from P to the bottom wire:
RP = 8 88 + 8 = 4
Req = 1 + 4 = 5
I = 105 = 2 A
The current divides equally between the two 8 paths from P: 1 A each.
The current of the right path (through 4 ) returns to the cell only through the ammeter.
Ammeter reading = 1 A
Answer: (2)