The resistor of resistance $R$ is connected to a $25\, V$ supply and the heat produced in it is $25\, J/s$. The value of $R$ is .......... $\Omega$.

An electric kettle takes $4 \ A$ current at $220 \ V$. If the entire electric energy is converted into heat energy, then the time (in minutes) taken to increase the temperature of $1 \ kg$ of water from $34^{\circ} C$ to $100^{\circ} C$ is

$A$ $60\,W$ bulb operates on a $220\,V$ supply. The current flowing through the bulb is:

$A$ heating element is designed to dissipate $2400 \, W$ when connected to $240 \, V$. The power it dissipates when it is connected to $120 \, V$ is (Assume that resistance of the filament is constant). (in $ \, W$)

$n$ identical bulbs,each designed to consume power $P$ at a certain voltage source,are connected in series across the same source. The total power consumed by them is:

Which of the following is not a unit of power?