# A farmer uses an aircraft to spray insecticide over a field. The insecticide droplets are given a static charge as they leave the spray nozzle. Explain how giving the droplets a static charge improves the effectiveness of the spray.

> Edexcel GCSE Physics (1PH0) — 11.1 Static electricity (Phys only) · Explain · 4 marks

> Farmers sometimes use aircraft to spray crops with insecticide. Modern spray systems charge the insecticide droplets as they are released from the nozzle.

## Mark scheme (4 marks)

1. The charged droplets all carry the same polarity / like charges
2. Like charges repel, so the droplets spread out evenly / repel each other
3. The charged droplets are attracted towards the earth / crop (unlike charges attract)
4. This reduces the risk of droplets blowing away / ensures more even / complete coverage of the crop

## Key terms

- [static charge](https://www.gradenine.co.uk/glossary/static-charge)

## Related

- [Revision notes for Edexcel GCSE Physics (1PH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-farmer-uses-an-aircraft-to-6214afad) · Published by Druglandscape Ltd.