The charge on an object in dry air keeps increasing. A spark eventually jumps between the object and a nearby earthed metal plate. What happens in the air during the spark?
The air is squeezed together by the strong electric field
The air gains protons from the surface of the charged object
The electric field is strong enough for charge to cross the air
The air is pushed out of the gap by the force on the charges
40 exam-style questions on AQA GCSE Physics 2.5 Static electricity, covering 2.5.1 Static charge and 2.5.2 Electric fields. Each one has a worked solution and a mark scheme showing where the marks go.