In the circuit shown below, the cell has an e.m.f. of 10V and internal resistance of 1ohm. The other resistance are shown in the figure. The potential difference Va-Vb is

-2 volt is the answer.

calculate the circuit current that comes out to be 2A.......now the resistances in parallel are equal...hence current through each branch is 1A..........now apply KVL in the loop made by the 4ohm & 2ohm

solve the equation.....

V_A+4-2=V_B

V_A-V_B=-2