What is the value of $1 \, kWh$ in Joules?

An electric bulb of $100\, W$ is connected to a supply of electricity of $220\, V$. The resistance of the filament is ............. $\Omega$.

The resistance of an electrical toaster has a temperature dependence given by $R(T) = R_0[1 + \alpha(T - T_0)]$ in its range of operation. At $T_0 = 300\,K, R = 100\,\Omega$ and at $T = 500\,K, R = 120\,\Omega$. The toaster is connected to a voltage source of $200\,V$ and its temperature is raised at a constant rate from $300\,K$ to $500\,K$ in $30\,s$. The total work done in raising the temperature is:

An amount of charge $Q$ passes through a coil of resistance $R$. If the current in the coil decreases to zero at a uniform rate during time $T$, then the amount of heat generated in the coil will be,

The ratio of heat dissipated per second through the resistance $5 \Omega$ and $10 \Omega$ in the circuit given below is:

An electrical power line, having a total resistance of $2 \, \Omega$, delivers $1 \, kW$ at $220 \, V$. The efficiency of the transmission line is approximately $....... \%$.