Six similar bulbs are connected as shown in the figure with a $DC$ source of $emf\; E$, and zero internal resistance. The ratio of power consumption by the bulbs when $(i)$ all are glowing and $(ii)$ in the situation when two from section $A$ and one from section $B$ are glowing, will be

If ${R_1}$ and ${R_2}$ are respectively the filament resistances of a $200$ $watt$ bulb and $100$ $watt$ bulb designed to operate on the same voltage, then

If in the circuit, power dissipation is $150\, W$, then $R$ is ............... $\Omega$

A resistance $R = 12\, \Omega$ is connected across a source of emf as shown in the figure . Its $emf$ changes with time as shown in the graph . What is the heat developed in the resistance in the first four seconds ? ............. $J$

Three electric bulbs of $200\,W,\,\,200\,W$ and $400\,W$ are shown in figure. The resultant power of the combination is ................ $W$

An electric kettle has two heating coils. When one coil is used, water in the kettle boils in $5$ minutes, while when second coil is used, same water boils in $10\,\min$. If the two coils, connected in parallel are used simultaneously, the same water will boil in time