Question

1. What is meant by electric current?
2. Name and define its unit.
3. Which instrument is used to measure the electric current? How should it be connected in a circuit?

Answer 1

1. (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.
2. 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" `
3. (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.