12V is probably short for 12 volts, the voltage used by regular car batteries.
And since 12V can strike a spark, it can be used to start a fire.
Fire steel is a piece of steel that can be used to create a spark for making fire.
Postulates
Coal, gunpowder, and blaze powder can be combined to create fire charges. Fire charges can be used as ammunition for dispensers or as a throwable item to create fire upon impact.
"Fire" is the answer. Just like scrap is used to make paper, fire is used to create smoke.
Yes
In Lord of the Flies the fire was used for it's smoke, to create a signal in the hope of being rescued, (which was more Ralph's desire for fire) where as Jack used the fire just as a cooking fire.
Flint, a hard, sedimentary cryptocrystalline form of the mineral quartz can create a fire by producing sparks when rubbed together when wet.
if used for charging-NO if used for supply voltage-yes
+12V, -12V, +5V, -5V, +3.3V -5V is seldom used
The mineral that can be used to create fire through rubbing pieces together is flint. When flint is struck against steel, such as in a flint and steel fire starter kit, it creates sparks that can ignite tinder.
Quartz!
Obviously they used fire and rocks for sparks, but u wouldn't guess that they actually used whale oil too