Two bulbs of $40\,W$ each are connected in parallel. The total power consumed by this combination is ............. $W$.

An electric bulb is rated $60\,W$,$220\,V$. The resistance of its filament is ............. $\Omega$.

Two wires '$A$' and '$B$' of the same material have lengths in the ratio $1 : 2$ and radii in the ratio $2 : 1$. If the two wires are connected in parallel to a battery,the ratio of heat produced in wire '$A$' to that in wire '$B$' will be:

An electric bulb marked $40\, W$ and $200\, V$,is used in a circuit of supply voltage $100\, V$. Now its power is (in $, W$)

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

$A$ 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 .............. $^oC$.