Two identical heaters rated $220\,V, 1000\,W$ are connected in series across a $220\,V$ supply. If the resistance does not change with temperature,the total power consumed by the combination is ............. $W$.

$A$ ring is made of a wire having a resistance $R_0 = 12\,\Omega$. Find the positions of points $A$ and $B$ such that the equivalent resistance of the circuit shown is $8/3\,\Omega$.

The ammeter reading in the circuit below is .............. $A$.

Two metal wires of identical dimensions are connected in series. If $\sigma_1$ and $\sigma_2$ are the conductivities of the metal wires respectively,the effective conductivity of the combination is

$A$ heating coil can heat the water of a vessel from $20\,^oC$ to $60\,^oC$ in $30$ minutes. Two such heating coils are put in series and then used to heat the same amount of water through the same temperature range. The time taken now will be ............ $min$ (neglecting thermal capacity of the coils).

The effective resistance across $AB$ in the network shown is .......... $\Omega$.