The variation of current $(I)$ and voltage $(V)$ is as shown in figure $A$. The variation of power $P$ with current $I$ is best shown by which of the following graph

Four bulbs $B_1 , B_2, B_3$ and $B_4$ of $100\, W$ each are connected to $220\, V$ main as shown in the figure. The reading in an ideal ammeter will be ............... $A$

If current in an electric bulb changes by $1\%$, then the power will change by ............ $\%$

Two identical batteries, each of $e.m.f.$ $2\, volt$ and internal resistance $1.0\, ohm$ are available to produce heat in an external resistance $R = 0.5\,ohm$ by passing a current through it. The maximum Joulean power that can be developed across $R$ using these batteries is ............. $watt$

A heater $A$ gives out $300\, W$ of heat when connected to a $200\, V$ $d.c.$ supply. Asecond heater $B$ gives out $600\, W$ when connected to a $200\,v$ $d.c$. supply. If a series combination of the two heaters is connected to a $200\, V$ $d.c$. supply the heat output will be ................. $W$

A constant voltage is applied between the two ends of a metallic wire. If both the length and the radius of the wire are doubled, the rate of heat developed in the wire