MC Q i dunno (1 Viewer)

[Tommy_Lamp]

this is the question...

"A current of 2.0A flows in a wire. The number of electrons passing a point on the wire each second is:
(A) 2.0
(B) 3.2x10^-19
(C) 6.3x10^18
(D) 1.3x10^19

has it got something to do with drift velocity?

i have no clue...thanks

 

[Tommy_Lamp]

Noone?

 

[wogboy]

Remember the basics first, just what is an electric current? It is the rate of flow of electric charges per unit time.

An Ampere is equal to a Coulomb of charge flowing per second. So 2A = 2 C/s.

So all the question is asking is for you to convert the current from Amperes (i.e. Coulombs per second), to electrons per second. You already know that one electron has a charge of -1.6*10^-19 Coulombs. With this in mind, you can find the number of electrons passing a point in the wire per second (no need to worry about the negative sign in this question). Give it a try, it's basically an excercise in converting units of measurement.

 

[Tommy_Lamp]

thanks