If voltage across a bulb rated $220 \text{ V} - 100 \text{ W}$ drops by $2.5\%$ of its rated value,the percentage of the rated value by which the power would decrease is ............... $\%$

An electric bulb rated $50 \, W-200 \, V$ is connected across a $100 \, V$ supply. The power dissipation of the bulb is: (in $ \, W$)

$A$ room heater is rated $400 \text{ W}$, $220 \text{ V}$. If the supply voltage drops to $200 \text{ V}$, what will be the power consumed (approximately) (in $\text{ W}$)?

If $10$ bulbs of $50\,W$ are used for $10$ hours a day,how many units of electricity will be consumed in a month ($30$ days)?

$A$ battery with a $12 \, V$ emf has an initial charge of $80 \, A \cdot h$. If the potential across the terminals stays constant until the battery is completely discharged, then this battery can deliver energy at the rate of $120 \, W$ for a time of: (in $ \, h$)

When three identical bulbs of $60\, W$,$200\, V$ rating are connected in series to a $200\, V$ supply,the power drawn by them will be ................ $W$.