In an experimental set-up as shown below,a piece of silver was placed touching points $A$ and $B$. Next time it was replaced by a piece of wood. In which case did the bulb glow? Give reason to justify the observation.

(N/A) The bulb will glow only when the piece of silver is placed between points $A$ and $B$.
Silver is a metal and acts as a good conductor of electricity,which completes the electrical circuit and allows current to flow through the bulb.
In contrast,wood is an insulator (a bad conductor of electricity). When a piece of wood is placed between points $A$ and $B$,it breaks the electrical circuit,preventing the flow of current,and therefore the bulb does not glow.