$A$ battery of $e.m.f.$ $3\, V$ and internal resistance $1.0\, \Omega$ is connected in series with a copper voltameter. The current flowing in the circuit is $1.5\, A$. The resistance of the voltameter will be ........... $\Omega$.

In the given figure, the current through the $4 \, \Omega$ resistor is ................. $A$.

The current flowing through the circuit shown in the figure is ........... $A$.

$A$ battery having $e.m.f.$ $5\,V$ and internal resistance $0.5\,\Omega$ is connected with a resistance of $4.5\,\Omega$. The voltage at the terminals of the battery is ............. $V$.

In the given circuit,the total power loss is $10 \text{ W}$. Find the value of resistance $R$ in $\Omega$.

Two equal resistances,$400 \Omega$ each,are connected in series with an $8 V$ battery. If the resistance of the first one increases by $0.5 \%$,what is the change required in the resistance of the second one in order to keep the potential difference across it unaltered?