conductors and batteries Flashcards
What are primary cells and what is their typical output?
used until flat and then replaced. The chemical
reaction that supplies the EMF in them is irreversible.
A typical carbon-zinc primary cell produces around 1.5V.
What are secondary cells and what is their typical output? Also what is an example?
use reversible chemical reactions (for example, lead-acid car batteries) and can be recharged and reused. Lead-acid cells usually produce around 2V.
What is the output of a solar/photo-voltaic cell?
about 0.4 – 0.6 volts each
What are piezo-electric cells and what is their typical output?
Crystals of certain materials will produce an EMF when they are put under mechanical pressure. The stronger the pressure applied, the greater the generated EMF. The EMF generated can range from 10mV to 10kV.
What are thermocouples and what is their typical output?
A thermocouple consists of a welded junction between two different metals. When the junction is heated, electrons move away from one of the metals towards the other metal. This produces a very small EMF in the range of 7mV to 80mV across the ends of the thermocouple.
