Humans were essentially hunters and gatherers. They had developed the use of fire. B â¦ ut they did not live a settled existence, instead following herds of animals on their migrations which were their primary source of food. Men were the hunters and responsible for the group's primary food source.
Emf - is the amount of energy of any form that is changed into electrical energy per coulomb of charge. pd - is the amount of electrical energy that is changed into other forms of energy per coulomb of charge. Sources of emf: Cell, battery (a combination of cells), solar cell, generator, dynamo, thermocouple.
Answers. 1  Sorry Bobweb, you got it wrong. The condensor, or capicator, stores the EMF discharged by the coil when the points open, and the collapsing force field generates a current in the secondary winding of the coil. Without the condenser, there is no spark when the points open. When the points open, the condenser is charged by the collapsing field i the coil, then the capicator discharges back through the coil, and this is what creates the voltage in the coil, which fires the plug.