$A$ copper voltameter is connected to a $12 \, V$ source,and $2 \, g$ of copper is deposited in $30 \, min$. If this cell is connected to a $6 \, V$ source,how much copper (in $g$) will be deposited in $45 \, min$?

Two wires $A$ and $B$ made of the same material and having their lengths in the ratio $6 : 1$ are connected in series. The potential differences across the wires are $3\,V$ and $2\,V$ respectively. If $r_A$ and $r_B$ are the radii of $A$ and $B$ respectively,then $\frac{r_B}{r_A}$ is

The reading of the ideal voltmeter in the adjoining diagram will be ................. $V$.

What is the equivalent resistance between $A$ and $B$ in the given infinite network?

The battery in the diagram is to be charged by the generator $G$. The generator has a terminal voltage of $120 \ V$ when the charging current is $10 \ A$. The battery has an $emf$ of $100 \ V$ and an internal resistance of $1 \ \Omega$. In order to charge the battery at $10 \ A$ charging current,the resistance $R$ should be set at ................ $\Omega$.

Find the equivalent resistance between points $A$ and $B$ in the network of resistors,each of resistance $r \Omega$.