obviously it is the battery with r1 resistance which will have zero potential diff.
just use kirchoff's loop law to find R .
E-ir1 + E - ir2 - iR = 0
E-ir1 =0 , i = E/r1
replacing in first eqn. ,
R= r1 - r2
obviously it is the battery with r1 resistance which will have zero potential diff.
just use kirchoff's loop law to find R .
E-ir1 + E - ir2 - iR = 0
E-ir1 =0 , i = E/r1
replacing in first eqn. ,
R= r1 - r2