Find the emf and internal resistance of a single battery which is equivalent to a combination of three batteries as shown in the figure.
3 V,2 Ω
Equivalent internal resistance, reff=1+(2||2)=1+2×22+2=1+1=2 Ω
Equivalent emf, Eeff=E3−E1r2−E2r1r1+r2=6−(10×2−4×22+2)=6−124=3 V