Insulators like wood and rubber have a very low electrical resistance.

Electric current flows through three lamps when arranged in $(a)$ a series and $(b)$ a parallel circuit. If the filament of one lamp breaks,explain what happens to the other two lamps in both cases.

Two conducting wires of the same material,equal length,and equal diameter are connected in series. How does the heat produced by the combination of resistance change?

Two bulbs are marked $60\, W, 220\, V$ and $100\, W, 220\, V$. These are connected in parallel to a $220\, V$ mains. Which one out of the two will glow brighter?

How does the resistivity of alloys compare with those of pure metals from which they may have been formed?

$n$ equal resistors are first connected in series and then connected in parallel. The ratio of the maximum to the minimum resistance is