
current in circuit $=\frac{12}{8}=\frac{3}{2} \mathrm{\,A}$
$\mathrm{V}_{\mathrm{A}}-\mathrm{V}_{\mathrm{B}}=9 \mathrm{V}$
$\mathrm{q}=\mathrm{C}\left(\mathrm{V}_{\mathrm{A}}-\mathrm{V}_{\mathrm{B}}\right)$
$=2 \times 9=18\, \mu \mathrm{C}$


| S.No. | $R$ | $l$ | $100-l$ | $S = \left( {\frac{{100 - l}}{l}} \right)R$ |
| $1$ | $20\,\Omega $ | $43$ | $57$ | $26.51\,\Omega $ |
| $2$ | $30\,\Omega $ | $51$ | $49$ | $28.82\,\Omega $ |
| $3$ | $40\,\Omega $ | $59$ | $41$ | $27.80\,\Omega $ |
| $4$ | $60\,\Omega $ | $70$ | $30$ | $25.71\,\Omega $ |
