$A$ rise of temperature of $4\,^oC$ is observed in a conductor by passing a current. If the current is tripled,the rise in temperature will be .............. $^oC$.

There are $n$ number of identical electric bulbs,each designed to draw a power $P$ independently from the mains supply. If they are now joined in series across the same mains supply,what is the total power drawn by the combination?

Two electric bulbs have power ratings $P_1$ and $P_2$ at voltage $V$. They are connected in parallel to a voltage source $V$. What is the total power consumed?

Two wires $A$ and $B$ of the same material and mass have their lengths in the ratio $1 : 2$. On connecting them to the same source, the rate of heat dissipation in $B$ is found to be $5\,W$. The rate of heat dissipation in $A$ is............ $W$

$A$ cell of internal resistance $r$ drives current through an external resistance $R$. The power delivered by the cell to the external resistance will be maximum when:

How many calories of heat will be produced approximately in a $210\, W$ electric bulb in $5$ minutes?