Question

A total charge of 9.0 mC passes through a cross-sectional area of a nichrome wire in 3.6s. The number of electrons passing through the cross-sectional area in 10s is

Answer 1

n = 1.56 x 10¹⁷ electrons

Step-by-step explanation:

First of all, we will calculate the current passing through wire:

`I = (q)/(t)`

where,

I = current = ?

q = charge = 9 mC = 0.009 C

t = time = 3.6 s

Therefore,

`I = (0.009\ C)/(3.6\ s)\\\\I = 0.0025\ A = 2.5\ mA`

Now, for the same current in 10 s time the charge will be:

q = It = (0.0025 A)(10 s)

q = 0.025 C

Now, the number of electrons can be given as:

`q = ne\\\\n = (q)/(e)\\\\`

where,

n = no. of electrons = ?

q = charge = 0.025 C

e = charge on single electron = 1.6 x 10⁻¹⁹ C

Therefore,

`n = (0.025\ C)/(1.6\ x\ 10^(-19)\ C)`

n = 1.56 x 10¹⁷ electrons