Conservation of charge
What Conservation of charge means in Physics A-Level, as defined for AQA, OCR.
Definitions of Conservation of charge
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Reference: AQA
Charge is conserved overall, for example the down quark charge of −1⁄3 changes to an up quark charge of +2⁄3 with the electron carrying away −1.
Charge must balance: the down quark has charge −1⁄3, while the up quark (+2⁄3), the electron (−1) and the antineutrino (0) sum to −1⁄3.
In any dc circuit, charge is neither created nor destroyed, so the current entering a junction equals the total current leaving it.
The principle that charge is conserved, which is why the sum of currents entering a junction equals the sum leaving it.
Proton number, or charge, must balance on both sides of a decay equation, and equations must balance proton number.
The total charge is the same on both sides of a nuclear transformation equation.
Topics that use Conservation of charge
- Applications of conservation laws (AQA A-Level)
- Circuits (AQA A-Level)
- Stable and unstable nuclei (AQA A-Level)
- Fundamental particles (OCR A-Level)
- Nuclear fission and fusion (OCR A-Level)
- Series and parallel circuits (OCR A-Level)
Related terms
- Conservation of energy
- Conservation of lepton number
- Conservation of nucleon number
- Lepton number conservation
- Nuclear stability
- Alpha and beta decay
- Alpha decay
- Anti-quark charge reversal
Using Conservation of charge in the exam
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