POTENTIAL

Interaction Potential Energy|Examples|Electric Potential Due To Point A Charge|Electric Potential Due To A Charged Rod|Electric Potential Due To A Ring|Electric Potential Due To A Disc|Electric Potential Due To A Shell|Electric Potential Due To A Solid Non Conducting Spehre

Consider the following relations for (i) EMF of the cell =(Oxidation potential of anode) -(Reduction potential of cathode) (iii) EMF of the cell=(Reduction potential of anode) + (Reduction potential of cathode) (iv) EMF of the cell=(Oxidation potential of the anode)-(Oxidation potential of the cathode) which of the following above reactions are correct?