A positively charged metal sphere is connected to Earth until it is neutral. The earth wire is removed. No other charged object is nearby. Which statement describes the sphere immediately after the wire is removed?
It becomes positive because electrons return to Earth after removal.
It becomes negative because electrons keep entering after removal.
It stays neutral because electrons entered and remain on the sphere.
It stays neutral because protons left and remain inside the Earth.
91 exam-style questions on Edexcel GCSE Physics 11.1 Charging by friction, covering 11.1.1 Charging insulators by friction, 11.1.2 Forces between charges, 11.1.3 Electrostatic phenomena, and 11.1.4 Earthing and removing charge. Each one has a worked solution and a mark scheme showing where the marks go.