An electric lamp is marked $60\, W$, $ 230\, V$. The cost of $1\, kilowatt$ hour of power is Rs. $1.25$. The cost of using this lamp for $8$ hours is Rs. ................

Four wires of the same diameter are connected in turn between two points, maintained at a constant potential difference. Their resistivities are; $\rho $ and $L$ (wire $1$ )., $1.2\,\rho $ and $1.2\,L$ (wire $2$ ), $0.9\,\rho $ and $0.9\,L$ (wire $3$ ) and $\rho $ and $1.5\,L$ (wire $4$ ). Rank the wires according to the rates at which energy is dissipated as heat, greatest first

The resistive network shown below is connected to a $D.C.$ source of $16\, V$. The power consumed by the network is $4\, Watt$. The value of $R$ is ............. $\Omega$

A current of $2\, mA$ was passed through an unknown resistor which dissipated a power of $4.4\, W$. Dissipated power when an ideal power supply of $11\, V$ is connected across it is

The energy consumed in $1\, Kwatt$ electric heater in $30$ seconds will be

In the circuit shown, the thermal power dissipated in $R_1$ is $P$. The thermal power dissipated in $R_2$ is