Question

A battery is connected in series with a resistor R. The battery transfers 2000 C of charge completely round the circuit. During this process, 2500 J of energy is dissipated R and 1500 J is expended in the battery. Calculate the emf of the battery. 

Answer 1

For a battery

E.m.f$=$ Total work done in moving a unit charge in a circuit

Total work done$=2500+1500=4000J$

E.m.f $=\frac{4000}{2000}=2V$