Why Copper wire is frequently used for conducting current?
Copper combines several properties that have traditionally made it preferred for most electrical wiring. Copper is a good electrical conductor, provides a good contact surface, is ductile (is easily bent repeatedly without breaking) and it is not too expensive. Copper wire is also relatively easy to manufacture, and there is a long history of using it.
What causes positive and negative charge?
There are number of factors that could b the cause of positive or negative charge e.g. Chemical Action , Heat , Light , Magnetic and Electric Fields.DOWNLOAD SOLUTION HERE