Two cells A and B with same e.m.f of 2 V each and with internal resistances `r_(A)=3.5Omega` and `r_(B)=0.5Omega` are connected in series with an external resistance `R=3Omega`. Find the terminal voltage across the two cells.

Explanation

Current through the circuit
`i=(epsilon)/((R+r))=(2+2)/((3+3.5+0.5))=(4)/(7)`
i) `R=3Omega, r_(A)=3.5Omega, E=2V,`
Terminal voltage A,
`V_(A)=E-ir =2-(4)/(7)xx3.5="0 volt"`
ii) `r_(B)=0.5Omega, R=3Omega, E=2V,`
Terminal voltage at B,
`V_(B)=E-ir=2-(4)/(7)xx0.5="1.714 volts."`