A current of 1A flows in a wire carried by electrons. How many electrons pass through the a cross-section of the wire each second?
This is a quite simple but really difficult question to me right now, and I put this as the heading because it is one of the most basics of questions.
So the charge of an electron is -1.6 x 10^(-19) C. If we look at the definition of what current is, it is the rate at which charge is moving.
But how are we supposed to find the number of electrons, without any other information?
Best Answer
I solved my own Question
$$Q=It$$
Since I=1A and we are interested when t=1 second. Therefore:
$$Q=1\cdot 1=1C$$
We know that the charge of 1 electron has the magnitude 1.6 x 10^(-19) C. Therefore we are looking for the solution to this equation:
$$\text{# Number of electrons x }1.6 \text{ x }10^{-19}=1C$$
$$\implies \text{Number of electrons}=6.25 \text{ x } 10^{18}$$