# Physics Topic: Current Electricity

Show an understanding that electric current is the rate of flow of charged particles.

Define charge and the coulomb.

Recall and solve problems using the equation

*Q = It.*Define potential difference and the volt.

Recall and solve problems using

*V = W/Q.*Recall and solve problems using

*P = VI, P = I*.^{2}RDefine resistance and the ohm.

Recall and solve problems using

*V = IR*.Sketch and explain the

*I-V*characteristics of a metallic conductor at constant temperature, a semiconductor diode and a filament lamp.Sketch the temperature characteristic of a thermistor.

Recall and solve problems using

*R=pL/A*.Define e.m.f. in terms of the energy transferred by a source in driving unit charge round a complete circuit.

Distinguish between e.m.f. and p.d. in terms of energy consideration.

Show an understanding of the effects of the internal resistance of a source of e.m.f. on the terminal potential difference and output power.