Question

Calculate the number of electrons passing a given point of wire if 0.2 ampere current is

flowing through the wire.
​

Answer 1

We have to find the number of electrons passing a given point of wire if 0.2 ampere current is flowing through it.

Solution : Current is the rate of charge flowing through a wire in a specific time. in short, current is the ratio of charge to time.

i.e., Q = it , where i is current , Q is charge and t is time.

Here, i = 0.2

as charge on each electron is e = 1.6 × 10^-19

We also know, Q = ne [ from quantisation of charge ]

now, n × 1.6 × 10^-19 = 0.2 × t

⇒n = (0.2/1.6 × 10^-19)/t = 1.25 × 10^18/t

if t = 1 sec

Then, n = 1.25 × 10^18

Therefore 1.25 × 10^18 electrons passing a given point of wire in a second.

Answer 2

To FinD :-

• The Number of electrons passing through a given wire if 0.2 Ampere current is flowing through the wire.

CalculaTioN :-

Current us the rate of flow of charge in a given conductor in a specified period of time.

This states that,

Q = IT, where

Q = Charge

I = Current

T = Time.

$\bold{ \pink{I = 0.2A}{} }{}$

$\bold{ \purple{★Charge \: on \: each \: e = 1.6 \times {10}^{ - 19} }{} }{}$

We Also Know that,

Q = ne [ From quantisation of charge ]

$n \times \frac{1.6 \times {10}^{ - 19} }{t} \\ \\ \bold{if \: t \: = 1}{} \\ \\ n = \frac{1.6 \times {10}^{ - 18=} }{1}=0.2*t \\ \\ \bold{ \red{n = 1.6 \times {10}^{ - 18} }{} }{}$