Question

Three different circuits (I, II and III) are constructed using identical batteries and resistors of R and 2R ohm. What can be said about current I in arm AB of each circuit.

A. I_I > I_II > I_III

B.  I_I < I_II < I_III

C. I_II < I_I < I_III 

D. I_I = I_II = I_III

Answer 1

The equivalent in all the three circuits comes out to be the same so I_I = I_II = I_III. The reason being, the two end resistors of R and R ohms add upto 2R and the subsequently the two resistors of 2R in parallel are equivalent to a single resistor of R ohms and then the process repeats until the arm AB is reached , so, finally the equivalent resistance of all the circuits is same.