An electric heater draws a current of $2\;A$ when connected to a voltage source of $120\;V$. What is the resistance of the heater coil?

What is the minimum resistance which can be made using five resistors each of $1/5\,\Omega$?

State Joule's law of heating and write its mathematical form.

The $V-I$ graphs for two resistors of the same material and the same radii with lengths $L_{1}$ and $L_{2}$ are shown below. If $L_{1} > L_{2}$, state with reason, which of these graphs represents voltage-current change for $L_{1}$?

$A$ bulb gets dimmer for a moment when a geyser,connected across the same source,is switched on. Why?

$A$ cylinder of a material is $10\, cm$ long and has a cross-section of $2\, cm^{2}$. If its resistance along the length is $20\, \Omega$,what will be its resistivity in number and units?