Given: \(E=10 V, r=3 \Omega, I=0.5 A, R=?, V=?\)
(i) \(\because\)
$$
\Rightarrow \quad \mathrm{R}+r=\frac{\mathrm{E}}{\mathrm{I}}=\frac{10}{0.5}=20
$$
$$
\text { or } \quad \begin{aligned}
\mathrm{R} &=20-r \\
\mathrm{R} &=20-3=17 \Omega
\end{aligned}
$$
(ii) \(\mathrm{V}=\mathrm{IR}=0.5 \times 17=8.5 \mathrm{~V}\)