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.
Generated Voltage from Changing B. The induced emf (generated voltage) can be calculated from Faraday's Law. According to Lenz's Law the induced current in the coil produces a magnetic field to oppose the change in magnetic field which produced it.Observing the direction of the.enerated Voltage from Changing B. The induced emf (generated voltage) can be calculated from Faraday's Law. According to Lenz's Law the induced current in the coil produces a magnetic field to oppose the change in magnetic field which produced it. Observing the direction of the.