$A$ wire of cross-sectional radius $r$ carries a current $I$ due to free electrons moving with a drift velocity $V$. What will be the current in another wire of the same material having half the radius and a drift velocity of $2V$?

Two wires $A$ and $B$ of the same material have lengths $L_A, L_B$ and radii $R_A, R_B$ and drift velocities $v_A, v_B$ respectively. Both wires carry the same current. If $L_A = L_B$ and $R_A = 2R_B$,then the value of $\left(\frac{v_A}{v_B}\right)$ is:

Current density in a cylindrical wire of radius $R$ varies with radial distance as $J(r) = \beta(r + r_0)^2$. The current through the shaded section of the wire shown in the figure is:

$A$ cylindrical wire of radius $0.5 \, mm$ and conductivity $5 \times 10^{7} \, S/m$ is subjected to an electric field of $10 \, mV/m$. The expected value of current in the wire will be $x^{3} \, \pi \, mA$. The value of $x$ is ......

Two identical conductors are kept at the same temperature. If the ratio of the potential difference across them is $1 : 2$,what will be the ratio of their drift velocities?

Electric current is due to the drift of electrons in