In the given figure,when key $A$ is opened,the reading of the ammeter $A$ will be ........... $A$.

In the circuit shown below,if the potential at point $A$ is taken to be zero,the potential at point $B$ is .............. $V$.

In the given circuit,the value of $\left|\frac{I_1+I_3}{I_2}\right|$ is

$A$ 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:

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?

$A$ series combination of two resistors $1\,\Omega$ each is connected to a $12\,V$ battery of internal resistance $0.4\,\Omega$. The current flowing through the circuit will be ............... $A$.