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.
PHY2054: Chapter 21 2. Voltage and Current in RLC Circuits. Ã®AC emf source: âdriving frequencyâ f. ÃIf circuit contains only R + emf source, current is simple. ÃIf L and/or C present, current is notin phase with emf. Ã®Z, Ïshown later. sin()m.