Refer to the figure given below, current between terminals A and B is A. [figure]
- 12.5
- 1.25
- 7.5
- 5
Answer
(2) 1.25
Solution
Each of the upper three rows: three 5 V cells in series (same polarity) and three 3 resistors ⇒ E=15 V, r=9 .
Three identical rows in parallel ⇒ Eeq=15 V, req= 93=3
Lowest row (from A to B): 3+3+3=9
The equivalent source and the 9 row form one closed loop:
[figure]
I= Eeqreq+9= 153+9= 1512
∴ I=1.25 A
Answer: (2)