During a thunderstorm, ice particles and water droplets in a cloud collide and rub against each other. The bottom of the cloud becomes negatively charged.
When enough charge has built up on the cloud, a lightning strike happens between the cloud and the ground.
A typical lightning strike has an average current of 25 kA25\ \text{kA}25 kA and lasts for 0.20 ms.
Explain how the cloud becomes charged and why lightning happens.
Use ideas about electrons and electric fields in your answer.
Include a calculation of the charge transferred by the lightning strike.
43 exam-style questions on OCR GCSE Physics 3.1 Static and charge, covering 3.1.1 Positive and negative charge, 3.1.2 Static electricity and forces between charged objects, 3.1.3 Electron transfer and static electricity, 3.1.4 Electric fields, 3.1.5 Current as a flow of charge, 3.1.6 Current in a single closed loop, and 3.1.7 Charge, current and time. Each one has a worked solution and a mark scheme showing where the marks go.