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

Power $P$ is to be delivered to a device via transmission cables having resistance $R_C$. If $V$ is the voltage across the device and $I$ is the current through it,find the power wasted and how can it be reduced.

If the resistance of the filament increases with temperature,what will be the power dissipated in a $220\, V- 100\, W$ lamp when connected to a $110\, V$ power supply?

The current flowing through a lamp marked as $50\, W$ and $250\, V$ is ............. $amp$.

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

In the circuit diagram,the heat produced in resistors $R$,$2R$,and $1.5R$ are in the ratio of: