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 ............... $A$
$0.45$
$0.90$
$1.35$
$1.80$
The power rating of an electric motor which draws a current of $3.75\, amperes$ when operated at $200\, V$ is about
How many calories of heat will be produced approximately in a $210\, watt$ electric bulb in $5$ minutes .............. $cal $
Two heater wires of equal length are first connected in series and then in parallel. The ratio of heat produced in the two cases is
The total power dissipated in watt in the circuit shown here is ............. $W$
A $220 \; V , 50 \; Hz$ AC source is connected to a $25 \; V$, $5 \; W$ lamp and an additional resistance $R$ in series (as shown in figure) to run the lamp at its peak brightness, then the value of $R$ (in ohm) will be