The terminal voltage of the battery, whose emf is $10 \, V$ and internal resistance is $1 \, \Omega$, when connected through an external resistance of $4 \, \Omega$ as shown in the figure is: (in $V$)

$A$ voltmeter of resistance $998\ \Omega$ is connected to a cell of $emf$ $2\ V$ and internal resistance $2\ \Omega$. The error in the measurement of $emf$ will be:

In the circuit shown,the power developed in the $6\,\Omega$ resistor is $6\,W$. The power developed in the $4\,\Omega$ resistor is .............. $W$.

$A$ student was trying to construct the circuit shown in the figure below marked $(a)$,but ended up constructing the circuit marked $(b)$. Realising her mistake,she corrected the circuit,but to her surprise,the output voltage (across $R$) did not change. The value of resistance $R$ is ............ $\Omega$

Two long coaxial and conducting cylinders of radius $a$ and $b$ are separated by a material of conductivity $\sigma$ and a constant potential difference $V$ is maintained between them by a battery. Then the current per unit length of the cylinder flowing from one cylinder to the other is -

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