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.
What is EMF? âEMFâ is an abbreviation for âelectric and magnetic fieldsâ and âelectromagnetic fields.â Power lines, appliances, and home wiring all produce electric and magnetic fields. âEMFâ is also often used by people as shorthand for just âmagnetic fields,â which some people are concerned about, so that is what âEMFâ refers to here. Download the PPL EMF Fact Sheet.