Question

Dr. John Cena is wiring his house and being the physicist he is wonders how many electrons pass him in a minute. When he measures the current it reads 6.0 mA. How many pass by him?

Answer 1

no. of electrons, n =
`2.25* 10^(18)` passes through his body

Step-by-step explanation:

We know the the rate of flow of charge is current and also amount of charge is an integral multiple of charge of an electron.

The two relations for current and charge are given as:

`I = (q)/(t)`

where

q = charge

I = current

t = time = 1 min = 60 s

So,
`q = I* t` (1)

Also,

q = ne (2)

n = 0, 1, 2,.....

e = charge of an electron =
`1.6* 10^(-19)` C

Using eqn (1) and (2):

`n = (I* t)/(e)`

`n = (6* 10^(-3)* 60)/(1.6* 10^(-19))`

n =
`2.25* 10^(18)`