$A$ new flashlight cell of $e.m.f.$ $1.5\, V$ gives a current of $15\, A$,when connected directly to an ammeter of resistance $0.04\,\Omega$. The internal resistance of the cell is ........... $\Omega$.

Resistances $R_1$ and $R_2$,each $60\,\Omega$,are connected in series as shown in the figure. The potential difference between $A$ and $B$ is maintained at $120\,V$. What will be the reading of the voltmeter connected between points $C$ and $D$ if the resistance of the voltmeter is $120\,\Omega$?

The resistance of a hot tungsten filament is about $10$ times its cold resistance. What will be the resistance of a $100\, W$ and $200\, V$ lamp when not in use? (in $\Omega$)

Find the ratio of currents as measured by the ammeter in two cases: when the key $K$ is open and when the key $K$ is closed.

In the given network,the current through branch $BG$ is almost equal to ............ $A$.

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