The standard reduction potentials, E∘, for the half-reactions are as Zn=Zn2++2e, E∘= + 0.76 V and Fe=Fe2++2e, E∘ = + 0.41 V. The e.m.f. for the cell reaction, Fe2++Zn=Zn2++Fe is
+ 0.35 V
Since oxidation potential of Zn is higher than Fe so it will act as an anode. Simultaneously, Fe will act as a cathode so EMF of the cell will be =E∘ (ox.) of Zn+E∘ (red) of Fe.