An Electric current

Figure 1

1. Hi guys...have you ever seen an instrument such as shown in Figure 1 ? What is the name and purpose of this instrument? It is an ammeter. Ammeter is used to measure an electric current.

Figure 2

2. Now look at Figure 2. The reading of the ammeter is 3 Amperes (3A). It shows that the current flow is 3A. What does it mean? It is the indication of the amount of electric charges that flow every second. It is because electric current, I, is the rate of flow of electric charges, I = Q/t, where Q is the amount of electric charges flow in Coulomb (C) and t is the time taken for the electric charges to flow in second (s).

3. The unit of an electric current is Ampere(A) which is equivalent to Coulomb/second