The flow of free electrons is called electric current. When electric pressure or voltage is applied, then free electrons, being negatively charged, will start moving towards the positive terminal round the circuit. This directed flow of free electrons is called electric current.
The actual direction of current is from negative terminal to the positive terminal through that part of the circuit external to the cell. However, prior to Electron Theory, it was assumed that current flowed from positive terminal to the negative terminal of the cell via the circuit. This convention is so firmly established that it is still in use. This assumed direction is now called conventional current.
The strength of electric current I is the rate of flow of electrons i.e., charge flowing per second.
Current, I = Q/t
Unit of electric current is coulombs/sec or ampere.
One ampere of current is said to flow through a wire if at any section one coulomb of charge flows in one second.
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