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

 

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(e) current as the movement of electrons in metals and movement of ions in electrolytes

 

(f) conventional current and electron flow

 

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(g) Kirchhoff’s first law; conservation of charge.

 

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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.

 

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