On some gas grills, there is a button you push which creates a spark to ignite the gas (propane, natural gas etc.)
My questions are probably pretty simple:
How does the button create the spark?
What voltage is this spark?
Almost all are piezo-electric. Check this Wikipedia page for info:
Piezo ignition is a type of ignition that is used in portable camping stoves, gas grills and some lighters. It consists of a small, spring-loaded hammer which, when a button is pressed, hits a crystal of PZT or quartz crystal. Quartz is piezoelectric, which means that it creates a voltage when deformed. This sudden forceful deformation produces a high voltage and subsequent electrical discharge, which ignites the gas.
And as Christopher Biggs commented:
the dielectric strength of dry air is about 33kV/cm, so if the spark jumps 2mm it has to be at least 6600v