In the given circuit,the current through the $2\,\Omega$ resistance is ............ $A$.

Four ammeters with identical internal resistance $r$ and a resistor $R$ are connected to a current source as shown. If the readings of $A_1$ and $A_2$ are $3 \, A$ and $5 \, A$ respectively,then the reading of $A_4$ is ............. $A$.

$A$ current of $1.5\, A$ flows through a copper voltameter. The thickness of copper deposited on the electrode surface of area $50\, cm^2$ in $20\, min$ will be (Density of copper $= 9000\, kg/m^3$ and $E.C.E.$ of copper $= 0.00033\, g/C$).

$A$ heater is rated $100\ W, 200\ V$. It is cut into two equal parts. Both parts are connected in parallel to the same $200\ V$ source. The energy released per second in this new combination is ............. $W$.

If a $30\, V, 90\, W$ bulb is to be operated on a $120\, V$ line,what resistance in ohms should be connected in series with the bulb?

If three bulbs $60\,W$,$100\,W$ and $200\,W$ are connected in parallel,then