7 (a) Which of the following shows the electric field around a point charge? (b) State one way of giving a rod a static electric charge - Edexcel - GCSE Physics - Question 7 - 2022 - Paper 1

One way to give a rod a static electric charge is by rubbing it with a material like wool or fur, which transfers electrons to the rod, resulting in a static charge.

The shape of the droplets from sprayer 1 is more spherical because they are negatively charged and repel each other, creating a more uniform distribution. In contrast, the droplets from sprayer 2 do not have a net charge, resulting in less repulsion, which leads to a more irregular shape.

Charging the droplets in the cloud of disinfectant causes them to be attracted to the seat due to induced charge. This means that even those droplets that aren’t directly in the line of the spray will still be attracted to the seat and distribute evenly across the surface, ensuring full coverage.

A build-up of static electric charge is dangerous because it can create a spark that may ignite flammable fuel vapors during refueling. This spark can easily lead to a fire or even an explosion, which poses significant risks to safety.

The danger is reduced by connecting the plane and the fuel tank with a metal wire that allows static charges to dissipate. This ensures that both the plane and the fuel are at the same potential, preventing static build-up during the refueling process.