
$A B$ is$V=\frac{\frac{E_{1}}{r_{1}}+\frac{E_{2}}{r_{2}}+\frac{E_{3}}{r_{3}}}{\frac{1}{r_{1}}+\frac{1}{r_{2}}+\frac{1}{r_{3}}}=\frac{\frac{3}{1}+\frac{2}{1}+\frac{1}{1}}{\frac{1}{1}+\frac{1}{1}+\frac{1}{1}}=2 V$




| Column $- I$ | Column $- II$ |
| $(A)$ Drift Velocity | $(P)$ $\frac{m}{n e^{2} \rho}$ |
| $(B)$ Electrical Resistivity | $(Q)$ $\mathrm{ne} v_{\mathrm{d}}$ |
| $(C)$ Relaxation Period | $(R)$ $\frac{\mathrm{eE}}{\mathrm{m}} \tau$ |
| $(D)$ Current Density | $(S)$ $\frac{E}{J}$ |