$n$ 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:

$A$ heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

How much heat (in $cal$) is produced when a $210 \, W$ bulb is kept on for $5 \, min$? (Given $J = 4.2 \, J/cal$)

$A$ wire of resistance $R$ is connected across a cell of emf $\varepsilon$ and internal resistance $r$. The current through the circuit is $I$. In time $t$,the work done by the battery to establish the current $I$ is

If a wire of resistance $20\,\Omega$ is covered with ice and a voltage of $210\,V$ is applied across the wire,then the rate of melting of ice is .................. $g/s$. (Take latent heat of fusion of ice $L = 80\,cal/g$ and $1\,cal = 4.2\,J$)

What amount of heat will be generated in a coil of resistance $R$ due to a charge $q$ passing through it if the current in the coil decreases to zero uniformly during a time interval $\Delta t$?