4.1 Charge and Current
4.1.1 Charge
Learners should be able to demonstrate and apply their knowledge and understanding of:
(a) electric current as rate of flow of charge;
(b) the coulomb as the unit of charge
(c) the elementary charge e equals 1.6 × 10–19 C Learners will be expected to know that an electron has charge –e and a proton a charge +e.
(d) net charge on a particle or an object is quantised and a multiple of e
(e) current as the movement of electrons in metals and movement of ions in electrolytes
(f) conventional current and electron flow
(g) Kirchhoff’s first law; conservation of charge.
4.1.2 Mean drift velocity
Learners should be able to demonstrate and apply their knowledge and understanding of:
(a) mean drift velocity of charge carriers
(b) I = Anev, where n is the number density of charge carriers
(c) distinction between conductors, semiconductors and insulators in terms of n.