A current of $2\, mA$ was passed through an unknown resistor which dissipated a power of $4.4\, W$. Dissipated power when an ideal power supply of $11\, V$ is connected across it is
$11\times10^{-5}\, W$
$11\times10^{-3}\, W$
$11\times10^{-4}\, W$
$11\times10^{5}\, W$
A $60\, watt$ bulb operates on $220\,V$ supply. The current flowing through the bulb is
he power dissipated in the circuit shown in the figure is $30\,W$. The value of $R$ is ............. $\Omega$
Heater of electric kettle is made of a wire of length $L$ and diameter $d$. It takes $4$ minutes to raise the temperature of $0.5 \ kg$ water by $40\ K$. This heater is replaced by a new heater having two wires of the same material, each of length $L$ and diameter $2 d$. The way these wires are connected is given in the options. How much time in minutes will it take to raise the temperature of the same amount of water by $40K$ ?
$(A)$ $4$ if wires are in parallel
$(B)$ $2$ if wires are in series
$(C)$ $1$ if wires are in series
$(D)$ $0.5$ if wires are in parallel.
If in the circuit, power dissipation is $150\, W$, then $R$ is ............... $\Omega$
The value of the resistance $R$ in figure is adjusted such that power dissipated in the $2\,\Omega$ resistor is maximum. Under this condition