Resistors, lamps and diodes

Resistors, lamps and diodes

Thermistors and LDRs

Thermistors are used as temperature sensors, for example in fire alarms. The resistance decreases as the temp increases.

LDRs are used to detect light levels, for example in automatic security lights. The resistance decreases as the light intensity increases.

Resistors

When resistors are connected in series, the total resistance of two or more resistors is the sum of their individual resistance.

When resistors are connected in parallel, the combined resistance of two or more resistors is less than that of either resistor by itself.

A resistor is an electrical component that restricts the flow of electric current. 

Lamps

The resistor of a lamp increases as the temp increases.

Filament lamps contain a thin coil of wire called the filament.

Potentiometers are variable resistors with a resistance control that is adjusted once and then fixed.

The current flowing through a filament lamp is not directly proportional to the voltage across it.

Diodes

Very high resistance in one direction. This means that the current can only flow in the…