Higher Tier: Uniform Electric Fields and Capacitors
Part of Static Electricity · GCSE GCSE Physics revision
This higher tier covers Higher Tier: Uniform Electric Fields and Capacitors within Static Electricity for GCSE Physics. Revise Static Electricity in Electricity for GCSE Physics with 15 exam-style questions and 12 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 12 of 15 in this topic. This section is most useful once the core foundation idea is secure, because it adds the detail that pushes answers higher.
Topic position
Section 12 of 15
Practice
15 questions
Recall
12 flashcards
🎓 Higher Tier: Uniform Electric Fields and Capacitors
This section is for AQA Higher tier (Grade 7–9). Foundation students do not need this.
Uniform Electric Fields
When two parallel metal plates are given opposite charges and placed facing each other, the electric field between them is uniform — the field lines are parallel, evenly spaced, and perpendicular to the plates.
- The field points from the positive plate to the negative plate
- The field is the same strength everywhere between the plates
- Outside the plates, the field is very weak and can be ignored
Uniform fields are used in cathode ray tubes, particle accelerators, and capacitors.
Capacitors (Introduction)
A capacitor consists of two parallel conducting plates separated by an insulator. When connected to a power supply, charge builds up on the plates — one plate becomes positive, the other negative. The capacitor stores electrical energy in the electric field between the plates.
- Capacitors charge up when connected to a voltage source
- They can discharge rapidly when needed (e.g., camera flash, defibrillator)
- The charge stored on a capacitor increases with the potential difference applied
Defibrillators use capacitors: charge is stored and then released in a short, controlled burst through the patient's chest, delivering the current needed to reset the heart rhythm.