$A$ cell of $e.m.f.$ $1.5\,V$ having a finite internal resistance is connected to a load resistance of $2\,\Omega$. For maximum power transfer,the internal resistance of the cell should be ............. $\Omega$.

Two sources of equal $emf$ $E$ are connected in series to an external resistance $R$. The internal resistances of the two sources are $R_1$ and $R_2$ $(R_2 > R_1)$. If the potential difference across the source having internal resistance $R_2$ is zero,then:

The storage battery of a car has an emf of $12 \ V$. If the internal resistance of the battery is $0.6 \ \Omega$,then the maximum current that can be drawn from the battery is . . . . . . . (in $A$)

If each resistance in the figure is of $9\,\Omega$,then the reading of the ammeter is ............ $A$.

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

Three light bulbs of $40\, W$,$60\, W$,and $100\, W$ are connected in series with a $220\, V$ source. Which one of the bulbs will glow brightest?