$A$ battery consisting of $6$ cells,each with an internal resistance of $0.5\, \Omega$ and an $e.m.f.$ of $2\, V$,is being charged by a $220\, V$ $D.C.$ mains using an external resistor of $10\, \Omega$. The charging current is: (in $, A$)

$A$ copper voltameter and a silver voltameter are connected in parallel. When a total charge $q$ flows through the voltameters,an equal mass of metal is deposited in each. If the electrochemical equivalents of copper and silver are $z_1$ and $z_2$ respectively,then the charge flowing through the silver voltameter is:

$A$ constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if

In the circuit shown,the current through the $4\,\Omega$ resistor is $1\,A$ when the points $P$ and $M$ are connected to a d.c. voltage source. The potential difference between the points $M$ and $N$ is ............... $V$.

When connected across the terminals of a cell,a voltmeter measures $5\,V$ and a connected ammeter measures $10\,A$ of current. $A$ resistance of $2\,\Omega$ is connected across the terminals of the cell. The current flowing through this resistance will be ............ $A$.

The figure shows a network of resistors and a battery. If $1\,A$ current flows through the branch $CF$,then find the $emf$ $E$ of the battery. (in $,V$)