$\mathrm{V}_{\mathrm{d}}=\frac{\mathrm{i}}{\mathrm{neA}}=\frac{1.6}{10^{29} \times 1.6 \times 10^{-19}} \times\left(10^{-3}\right)^{2}$
$=\frac{1}{10^{10} \times 10^{-6}}=10^{-4} \mathrm{\,m} / \mathrm{sec}$
| List $I$ | List $II$ |
| $(I)$ Two wires of same resistance are connected in series and same current is passed through them | $(A)$ $1:2$ |
| $(II)$ Two wires of resistance $R$ and $2R$ $ohm$ are connected in series and same $P . D .$ is applied across them | $(B)$ $4:1$ |
| $(III)$ Two wires of same resistance are connected in parallel and same current is flowing through them | $(C)$ $1:1$ |
| $(IV)$ Two wires of resistances in the ratio $1: 2$ are connected in parallel and same $P . D .$ is applied across the | $(D)$ $2:1$ |





$(A)$ The current through $P Q$ is zero.
$(B)$ $I_1=3 A$.
$(C)$ The potential at $S$ is less than that at $Q$.
$(D)$ $I _2=2 A$.

