Question 4
In activity 19.1 one terminal of the neon bulb must be connected to a wire that is well earthed. Why?
The right answer is the one marked above.
To give the charges somewhere to flow away to. The stored charge on the rod needs a complete path before it will move. Earthing one end provides that path, and the charge flows through the bulb on its way.
Without the earth connection nothing flows and the bulb stays dark — which is exactly why the bird on the wire at the end of this chapter is unharmed.