Current electricity is the study of charges in motion. It consists of positive and negative charges called electric current, which is measured in Amperes. Electric current is produced by a source of electromotive force and is defined by Ohm's law, where voltage is equal to current times resistance. Resistance depends on the resistivity, length, and cross-sectional area of the material. The standard units for charge, current, voltage, resistance, and work are coulombs, amperes, volts, ohms, and joules respectively.

1. TOPIC 11 Summary

2. CURRENT ELECTRICITY is a study of Consists of positive and negative charges. Moving charges, Q S.I. unit for Q : C ( coulomb)

3. Electric current, I Constitutes an Formula I = where t is time in seconds S.I. unit for I: A (Ampere) Moving charges, Q

4. S.I. unit : V (voltage) Produced by E = where W = work done by source Formula e.m.f., e Electric current, I

5. S.I. unit : V (voltage) Established by Electric current, I V= , W is electrical energy converted Formula Potential Difference, p.d., V

6. Potential Difference, p.d., V Resistance, R R = S.I. unit for R: Ω, Ohms Electric current, I

7. R = ρ = resistivity l = length A = cross sectional area

8. S.I. unit : V (voltage) Produced by Established by CURRENT ELECTRICITY S.I. unit for Q : C ( coulomb) Electric current, I Constitutes an Formula is a study of Consists of positive and negative charges Q Moving charges, Q I = where t is time in seconds) S.I. unit for I: A (Ampere) V= , W is electrical energy converted Formula Potential Difference, p.d., V E = where W = work done by source Formula e.m.f., e Resistance, R Formula R = S.I. unit for R: Ω, Ohms ρ = resistivity l = length A = cross sectional area