Why repulsion is the sure test of electrification?

since the ammeter is connected directly into the circuit, it must have a low resistance so that it does not reduce the flow of charge, which it is being used to measure current.

Lightning rods are pointed so a charge will be concentrated at the end. If the rod had a round end the charges would spread equally around its surface. ... As long as the air is prevented from ionizing it won't conduct the lightning bolt.

Coulomb is the unit of electric charge which is defined as the amount of electric charge that passes through a surface at the rate of one ampere per second. The coulomb is abbreviated as "C".

The statcoulomb (abbreviated as "statC") is a unit of electric charge that is equal to the amount of charge in 1 statcoulomb of charge. One statcoulomb is defined as the charge that is transported in one second by a current of one statampere. The statcoulomb is a unit that is used in the CGS system of...