Two wires made of the same material have lengths in the ratio $2: 3$ and radii in the ratio $8: 9$. If the same potential difference is applied across the ends of the wires,the ratio of the electric currents flowing through them is

In the following circuit diagram,$E = 4\,V, r = 1\,\Omega$ and $R = 45\, \Omega$,then the reading of the ammeter $A$ will be

In the figure shown,the capacity of the capacitor $C$ is $2\,\mu F$. The current in the $2\,\Omega$ resistor is ............... $A$.

$A$ $d.c.$ main supply of $e.m.f. \, 220 \, V$ is connected across a storage battery of $e.m.f. \, 200 \, V$ through a resistance of $1 \, \Omega$. The battery terminals are connected to an external resistance $'R'$. The minimum value of $'R'$ so that a current passes through the battery to charge it is ............... $\Omega$.

In the figure shown,the total resistance between $A$ and $B$ is ............. $\Omega$.

In the circuit shown,the cells $A$ and $B$ have negligible internal resistances. For $V_A = 16 \ V$,$R_1 = 600 \ \Omega$,and $R = 200 \ \Omega$,the galvanometer shows no deflection. The value of $V_B$ is $...V$.