Question

A copper wire of cross sectional area 2.0mm2 carries a current of 10A. How many electrons pass through a given cross section of wire in one second?

A 1.0×10^1. B 5.0×10^6. C 6.3×10^19. D 3.1×10^25

Answer 1

The amount of electron that pass through the wire is 6.3*10^19. (Option C)

Step-by-step explanation:

The current represent the amount of electriccharge iper period of time. When the current is in Ampere (A) the charge is expressed in Coulombs (C) and the time in seconds (s).

I=Q/T

Solving for Q and replacing the value for the current an a time of 1 seconds:

Q=I.T = 10 A * 1s = 10 C/s * 1s = 10 C

The amount of electrons is calculated by dividing the total charge by the charge of one electron. Recall for the charge of a one electron q is:

q=1.6*10^-19 C

Number of electrons = 10 C / 1.6*10^-19 C = 6.3*10^19