In the circuit, wire \(1\) is of negligible resistance. Then:
1. | current will flow through wire \(1\) if \(E _{1}\neq E _{2}\) |
2. | current will flow through wire \(1\) if \(\dfrac{E _{1}}{R_{1}}\neq \dfrac{E _{2}}{R_{2}}\) |
3. | current will flow through wire \(1\) if \((E_{1} +E _{2})\left ( R_{1}+R_{2} \right )\neq (E_{1} -E _{2})\left ( R_{1}-R_{2} \right )\) |
4. | no current will flow through wire \(1\) |