moar physics Flashcards
Resistance in a LDR (light dependent resistor)
Resistance decreases as light intensity increases
Resistance of a thermistor
resistance of a thermistor decreases as temperature increases
what is a diode
a diode is a semiconductor device that essentially acts as a one-way switch for current. It allows current to flow easily in one direction, but severely restricts current from flowing in the opposite direction.
If the voltage across a diode is negative, no current can flow*, and the ideal diode looks like an open circuit. In such a situation, the diode is said to be off or reverse biased. As long as the voltage across the diode isn’t negative, it’ll “turn on” and conduct current.
Main use: Rectifying current, can also be used as a light (LED)
What is an LED
a semiconductor light source that emits light when current flows through it
The LED is a polar device, it matters which way round it is connected into a circuit
