A battery of emf 2.0 V and internal resistance `0.50(Omega)`supplies a current of 100 mA. Find (a) the potential difference across the terminals of the battery and (b) the thermal energy develop in the battery in 10 s.

Explanation

(a) The potential difference across the terminals is
`V_(A)-V_(B)=(V_(A)-V_(C))-(V_(B)-V_(C))`
`=(epsilon)-ir.`
`2.0V-(0.100A)(0.50(Omega))=1.96V.`
`The thermal energy develop in the battery is
`U=i^(2)rt=(0.100A)^(2)(0.50(Omega))(10s)=0.05 J.`