IB Physics B.5.5 Electric Cells and Variable Resistors Key Definitions

The electromotive force (emf) is the work done per unit charge to move a charge completely around a circuit, including through the battery.

Internal resistance is the resistance within the battery itself, caused by the materials and chemical reactions inside it.

A light-dependent resistor (LDR) is a resistor whose resistance decreases as the intensity of light falling on it increases.

A potentiometer is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider.

A thermistor is a resistor whose resistance changes with temperature.

Variable resistors are components that allow you to adjust the resistance in a circuit.