In the circuit, wire 1 is of negligible resistance. Then,
(a) current will flow through wire 1, if ε1 ≠ ε2
(b) current will flow through wire 1, if ε1/R1 ≠ ε2/R2
(c) current will flow through wire 1, if \(\frac{\varepsilon_1+\varepsilon_2}{(R_1+R_2)} \neq\frac{\varepsilon_1-\varepsilon_2}{(R_1-R_2)}\)
ε1+ε2/(R1+R2) ≠ ε1-ε2/(R1-R2)
(d) no current will flow through wire 1