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}R.

Define resistance and the ohm.

Recall and solve problems using V = IR.

Sketch and explain the IV 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.