What is emf?

when are we exposed to emf?

does emf increase or decrease with distance?

what are the primary differences in direct current and alternating current?

Electricity is the voltage produced by any electrical energy source such as battery or dynamo. EMF increase with distance.

The direct current is fixed but the alternating current is constantly changing

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.