The current from the battery in the given circuit is ................ $A$.

For the circuit shown,with $R_1 = 1.0\,\Omega$,$R_2 = 2.0\,\Omega$,$E_1 = 2\,V$ and $E_2 = E_3 = 4\,V$,the potential difference between the points $a$ and $b$ is approximately (in $V$):

In the given circuit,the galvanometer reading is zero. If the internal resistance of the cells is negligible,then the value of $x$ is ............. $\Omega$.

Determine the current in each branch of the network shown in the Figure.

$A$ Wheatstone's bridge is balanced with a resistance of $625\, \Omega$ in the third arm,where $P, Q$ and $S$ are in the $1^{st}, 2^{nd}$ and $4^{th}$ arm respectively. If $P$ and $Q$ are interchanged,the resistance in the third arm has to be increased by $51\,\Omega$ to secure balance. The unknown resistance in the fourth arm is ............. $\Omega$.

In the given circuit,find the potential difference between $P$ and $Q$ in $V$.