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

$A$ resistor dissipates $192 \, J$ of energy in $1 \, s$ when a current of $4 \, A$ is passed through it. Now,when the current is doubled,the amount of thermal energy dissipated in $5 \, s$ is $..... \, J$.

The maximum power drawn from a source with electromotive force $E$ and internal resistance $r$ is given by:

$A$ $10\, \Omega$ electric heater operates on a $110\, V$ line. Calculate the rate at which it develops heat in $watts$.

How many electrons per second flow through a filament of a $120 \ V$,$60 \ W$ electric bulb?

$A$ button battery is rated $3 \,V$ and $225 \,mAh$. $A$ cricket ball (mass $= 0.163 \,kg$) having energy equal to that stored in the battery will have a speed closest to ............ $\,m/s$.