What is the resistance of a $100 \, W, 220 \, V$ bulb in $\Omega$?

$A$ circular wire has a current density $J = (2 \times 10^{10} \text{ A/m}^2) r^2$, where $r$ is the radial distance from the center and the wire radius is $2 \text{ mm}$. The potential difference applied across the wire is $50 \text{ V}$. How much energy (in Joules) is converted to thermal energy in $100 \text{ s}$ (in $\pi$)?

The amount of heat produced in a resistor when a current is passed through it can be found using

$A$ $5\;A$ fuse wire can withstand a maximum power of $1\;W$ in the circuit. The resistance of the fuse wire is

How many $60 \,W$ bulbs may be safely run on $220 \,V$ using a $5 \,A$ fuse?

$A$ wire of resistance $R$ is connected across a cell of emf $\varepsilon$ and internal resistance $r$. The current through the circuit is $I$. In time $t$,the work done by the battery to establish the current $I$ is