In the given circuit,for maximum power to be transferred from a battery with an internal resistance of $4\, \Omega$,what should be the value of $R$ in $\Omega$?

If the ammeter in the given figure shows a reading of $2 \, A$,find the value of $R$ in $\Omega$.

In the adjoining circuit shown,the potential difference between points $A$ and $B$ will be:

The resistance of an iron wire is $10\,\Omega$ and the temperature coefficient of resistivity is $5 \times 10^{-3}\,^{\circ}C^{-1}$. At $20\,^{\circ}C$,it carries $30\,mA$ of current. Keeping the potential difference between its ends constant,the temperature of the wire is raised to $120\,^{\circ}C$. The current in milliamperes that flows in the wire is:

In the given circuit,the power generated in the $1 \, \Omega$ resistance will be maximum for $x$ equal to ................ $\Omega$.

$A$ voltmeter of resistance $1000\,\Omega$ is connected across a resistance of $500\,\Omega$ in the given circuit. What will be the reading of the voltmeter in $V$?