In working with electric charges either standing still or in motion as current flow, you will need some unit measuring for the amount of electric charge. the basic unit of electric charge is the electron but, since its, charge is extremely small and the electron itself is so small that it cannot be seen, you will need to use a more practical unit for measurement.

   You are the measurement of gain, for example. each kernel of gain is much too small to be used as a practical unit of measurement. therefore the bushel, containing the several million karnals, is the practical unit are used. similarly, water is not measurement counting drops of water. instead, a unit called the quart is used.  for measuring the electric charge the unit used is the coulomb. , which is approximately 6.28 million, million, million electrons.

The coulomb measurement is the quantity of electric charge or the number of electrons regardless of whether the charge is in motion or standing still.

Units of current flow:-

Current flow is measured as how many electrons are passing through a material in a given length of time. The coulomb measurement is the number of electrons so that, by counting the coulombs which pass in a given amount of time, the current flow is the measure. the unit of current flow is the ampere . one ampere of current is flowing when one coulomb of electrons passing through the material is one second,  two amperes when two-coulomb pass per second, etc.

Since ampere means coulomb per second, the ampere is a measure of the rate of electrons are moving through the materials. the coulomb , which represents the number of electrons in a charge, is a measure of quantity. 

 Measuring unit of current flow:-

In working with electricity, a means of measuring current flow through a material is necessary. an ammeter did this; it indicates in amperes the number of electrons passing per second.

When the amount of current flowing through a circuit is to be measured, the ammeter is always connected in series with the line that delivers the currents to the circuit; it will be damaged if it is connected in any other way. become a matter indicating the rate of electrons movement just as a meter in a water system shows the rate at which gallons of water are used, it flows that in order to show correctly the amount of current being used, the meter must be connected into the line (by breaking or opening the line to insert it.)