A region at the bottom of a cloud becomes negatively charged. Before a lightning discharge, electrons in the ground beneath it move away from the surface. Which statement explains what happens next?
The surface becomes negative; electrons can discharge from the cloud to the ground.
The surface becomes positive; protons can discharge from the ground to the cloud.
The surface becomes positive; electrons can discharge from the cloud to the ground.
The surface becomes negative; protons can discharge from the ground to the cloud.
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.