(a)[3]
With reference to the circuit shown in Fig. 4.1, distinguish between the definitions of e.m.f. and p.d.
(b)[1]
Using Kirchhoff’s second law, determine an expression for the current $I$ in the circuit.
(c)
The way the p.d. $V$ across $R$ varies with current $I$ is shown in Fig. 4.2. Use Fig. 4.2 to determine (i) the e.m.f. $E$, and (ii) the internal resistance $r$.
(c(i))[1]
Determine the e.m.f. $E$.
(c(ii))[2]
Determine the internal resistance $r$.
(d(i))[2]
Using data from Fig. 4.2, calculate the power transferred to $R$ for a current of $1.6\,\text{A}$.
(d(ii))[2]
Use your answers from c(i) and d(i) to calculate the efficiency of the battery for a current of $1.6\,\text{A}$.