An electric bulb is marked $100\ W, 230\ V$. If the supply voltage drops to $115\ V$,how much heat (in $J$) is produced by the bulb in $20\ min$?

$A$ student in a town in India,where the price per unit $(1 \text{ unit} = 1 \,kWh)$ of electricity is $₹ 5.00$,purchases a $1 \,kVA$ $UPS$ (uninterrupted power supply) battery. $A$ day before the exam,$10$ friends arrive at the student's home with their laptops and all connect their laptops to the $UPS$. Assume that each laptop has a constant power requirement of $90 \,W$. Consider the following statements.
$I.$ All the $10$ laptops can be powered by the $UPS$,if connected directly.
$II.$ All the $10$ laptops can be powered,if connected using an extension box with a $3 \,A$ fuse.
$III.$ If all the $10$ friends use the laptop for $5 \,h$,then the cost of the consumed electricity is about $₹ 22.50$.
Select the correct option with the true statements.

An electric power line having a total resistance of $2 \ \Omega$ delivers $1 \ kW$ of power at $250 \ V$. The percentage efficiency of the transmission line is: (in $\%$)

If the current through a resistor in a circuit increases by $3 \%$,then the power dissipated by the resistor

$A$ 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$)

An electric bulb is designed to draw power $P_0$ at voltage $V_0$. If the voltage is $V$,it draws a power $P$. Then: