$A$ 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 $45 \, min$?

$A$ cell of emf $1.8 \ V$ gives a current of $17 \ A$ when directly connected to an ammeter of resistance $0.06 \ \Omega$. The internal resistance of the cell is: (in $\Omega$)

When an ammeter of negligible internal resistance is inserted in series with the circuit,it reads $1 \, A$. When a voltmeter of very large resistance is connected across $X$,it reads $1 \, V$. When points $A$ and $B$ (across $Y$) are shorted by a conducting wire,the voltmeter measures $10 \, V$ across the battery. The internal resistance of the battery is equal to .............. $\Omega$.

One end each of a resistance $r$,a capacitor $C$,and a resistance $2r$ are connected together. The other ends are respectively connected to the positive terminals of batteries $P$,$Q$,and $R$ having emfs $E$,$E$,and $2E$. The negative terminals of the batteries are then connected together. In this circuit,with steady current,the potential drop across the capacitor is:

Two bulbs $X$ and $Y$ have the same voltage rating and their power ratings are $40 \ W$ and $60 \ W$ respectively. They are connected in series to a $300 \ V$ battery as shown in the figure. Then:

In the circuit shown below,the cell has an $e.m.f.$ of $10\,V$ and internal resistance of $1\,\Omega$. The other resistances are shown in the figure. The potential difference ${V_A} - {V_B}$ is ................ $V$.