(a) What is meant by electric current ? Give its direction ?
(b) Name and define its unit.
(c ) Which instrument is used to measure the electric current ? How should it be connected in a circuit ?

Explanation

(a) (i) Electric current is often termed as .current. and it is represented by the symbol .I. It is defined as the rate of flow of charges in a conductor.
(ii) The electric current represents the amount of charges flowing in any cross section of a conductor (say a metal wire) in unit time.
(b) The SI unit of electric vurrent is ampere (A). The current flowing through a conductor is said to be one ampere, when a charge of one coulomb flows across any cross - section of a conductor in one second. Hence,
1 ampere `=("1 coulomb")/("1 second")`
(c ) (i) Ammeter is used to measure the current.
(ii) An Ammeter is connected in series with circuit.
(iii) The Ammeter is a low impedance device connecting it in parallel with the circuit would cause a short circuit, damaging the Ammeter or the circuit.