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

$A$ given quantity of water is boiled by an electric heater in $5 \text{ min}$. If the supply voltage of the heater is reduced to half,then the time taken to boil the same quantity of water will be . . . . . . $\text{min}$. (Assume the resistance of the heater remains constant.)

In a $Ag$ voltameter,$2.68 \, g$ of silver is deposited in $10 \, \min$. The heat developed in a $20 \, \Omega$ resistor during the same period will be:

In an electric heater, $4\, A$ current passes for $1\, \text{minute}$ at a potential difference of $250\, V$. The power of the heater and the energy consumed will be, respectively:

$A$ $10\, V$ storage battery of negligible internal resistance is connected across a $50\,\Omega$ resistor. How much heat energy is produced in the resistor in $1$ hour? (in $J$)

Heat produced in a wire of resistance $R$ due to current flowing at constant potential difference is proportional to