* number 1 : the current will flow normally: Correct
* number 2 : the voltage source will not give current but Vb-Va = V of the voltage source : Correct
* number 3 : no current will flow: Incorrect, there will be current and the voltage will be infinite across the current source
* number 4 ...
Say you have salt water. If you apply an voltage between two electrodes Na+ ions will drift towards the negative electrode and Cl- ions towards the positive electrode. If a redox reaction happens at the electrodes, the ions transfer electrons to the electrodes and current continues to flow until...