An electric lamp is marked $60\, W$, $230\, V$. The cost of a $1\, kWh$ of energy is Rs. $1.25$. The cost of using this lamp $8$ hrs a day for $30$ day is Rs. ...............

Three light bulbs of $40\, W$, $60\, W$ and $100\, W$ are connected in series with $220\, V$ source. Which one of the bulbs will glow brightest ............ $W$

Incandescent bulbs are designed by keeping in mind that the resistance of their filament increases with the increase in temperature. If at room temperature, $100 \mathrm{~W}, 60 \mathrm{~W}$ and $40 \mathrm{~W}$ bulbs have filament resistances $\mathrm{R}_{100}, \mathrm{R}_{60}$ and $\mathrm{R}_{40}$, respectively, the relation between these resistances is

Wheat stone bridge is balanced. Find ratio of electric power dissipated in $(P + Q)$ to $(R + S)$

In the following circuit composed of identical resistors, across which terminals would you connect a battery in order to dissipate energy in all resistors 

An electrical bulb rated $220\,V , 100\,W$, is connected in series with another bulb rated $220\,V$, $60\,W$.If the voltage across combination is $220\,V$, the power consumed by the $100\,W$ bulb will be about $........... W$