In the circuit shown, if a conducting wire is connected between points A and B, the current in this wire will
-
flow from A to B
-
flow in the direction which will be decided by the value of V
-
be zero
-
flow from B to A
D.
flow from B to A
Current will flow from higher to lower potential.
Resistances 
are connected in series, so their effective resistance is 
Similarly, 
and 
are in series
So, 
Now R' and R" will be in parallel, hence effective resistance
Current through the circuit, from Ohm's law
Let current 
flow in the branches as shown:
Since, drop of potential is greater in 
resistance so. It will be at lower potential than B, hence, on connecting wire between points A and B, the current will flow from B to A.
