$4$ bulbs marked $40\, W$, $250\, V$ are connected in series with $250\, V$ mains. The total power is ............. $W$

Two electric bulbs, rated at $(25\, W, 220\, V)$ and $(100\, W, 220\, V)$, are connected in series acroos a $220\, V$ voltage source. If the $25\, W$ and $100\, W$ bulbs draw powers $P_1$ and $P_2$ respectively, then

Two equal resistances when connected in series to a battery, consume electric power of $60\,W.$ If these resistances are now connected in parallel combination to the same battery, the electric power consumed will be .............. $W$

The same mass of copper is drawn into two wires $1\, mm$ and $2\, mm$ thick. Two wires are connected in series and current is passed through them. Heat produced in the wire is in the ratio

The energy dissipated by a resistor is $10 \,mJ$ in $1\,s$ when an electric current of $2\, mA$ flows through it. The resistance is $....... \Omega$

(Round off to the Nearest Integer)

Two electric bulbs whose resistances are in the ratio of $1 : 2$ are connected in parallel to a constant voltage source. The powers dissipated in them have the ratio