Question

a current of 8 ampere is flowing through a conductor. How many electrons pass through its cross - section in one minute ?​

Answer 1

Given,

A current of 8 ampere is flowing through a conductor.

To find :

How many electrons pass through its cross - section in one minute.

Solution :

Given values :

Current = 8A

Charge on an electron = 1.6 × 10⁻¹⁹ C

Time = 1 minute = 60 s

Let the number of electrons passing through its cross section be 'n'

Now we know,

I = q/t

Where, I = Current

q = charge

t = time

Also, q = ne

Where, n = number of electrons

e = charge on electron

Therefore,

I = ne/t

⇒ 8 = (n * 1.6 × 10⁻¹⁹)/60

⇒ 8 * 60 = n * (1.6 × 10⁻¹⁹)

⇒ 480 = n * (1.6 × 10⁻¹⁹)

⇒ n = 480/(1.6 × 10⁻¹⁹)

⇒ n = 3 × 10²¹

Therefore,

Number of electrons passing through its cross section in 1 minute = 3 × 10²¹

Answer 2

$\huge{\boxed{\rm{\red{Question}}}}$

A current of 8 ampere is flowing through a conductor. How many electrons pass through its cross - section in one minute ?

$\huge{\boxed{\rm{\red{Answer}}}}$

$\large{\boxed{\boxed{\sf{Given \: that}}}}$

• A current of 8 ampere is flowing through a conductor.

$\large{\boxed{\boxed{\sf{To \: find}}}}$

• How many electrons pass through its cross - section in one minute.

$\large{\boxed{\boxed{\sf{Solution}}}}$

• 3 × 10²¹ is the number of electrons pass through its cross - section in one minute.

$\large{\boxed{\boxed{\sf{What \: the \: question \: says \: ?}}}}$

$\large{\boxed{\boxed{\sf{Let's \: understand \: the \: concept \: 1{st}}}}}$

• This question says that we have to find total numbers of electrons pass through its cross - section in one minute. And it's given that current of 8 ampere is flowing through a conductor.

$\large{\boxed{\boxed{\sf{How \: to \: do \: this \: question}}}}$

$\large{\boxed{\boxed{\sf{Procedure \: is \: given \: below}}}}$

• As we know that the value of electrons that pass through its cross - section in one minute is not given to us. We have to find it. So we have to assume the value we assume it as n. After that using the formula of current we have to substitute the values afterwards we have to put the values according to the formula. At last we get our answer.

$\large{\boxed{\boxed{\sf{Assumption}}}}$

• Let n as the number of electrons pass through its cross - section in one minute.

$\large{\boxed{\boxed{\sf{Full \: solution}}}}$

$\large\purple{\texttt{According to the question}}$

We have to find the values of electrons pass through its cross - section in one minute.

Hence, we already let the values of electrons pass through its cross - section in one minute as n.

$\large{\boxed{\boxed{\sf{Using \: formula \: is \: given \: below}}}}$

$\large{\boxed{\boxed{\sf{Using \: formula \: is \: of \: Current}}}}$

$\large\underbrace\mathfrak\orange{Formula \: to \: find \: current}$

$\bold{\pink{\fbox{\green{l = q/t}}}}$

• l means current

• q means charge

• t means time

$\large\purple{\texttt{We also know that}}$

$\bold{\pink{\fbox{\green{q = ne}}}}$

Value of given formula -

• n means number of electrons

• e means charge on electrons

$\large\orange{\texttt{Therefore , substituting the values}}$

$\large\purple{\texttt{We get following results}}$

$\bold{\pink{\fbox{\green{l = ne/t}}}}$

$\large\orange{\texttt{Therefore , putting the values}}$

$\leadsto$ 8 = ( n × 1.6 × 10-¹⁹ ) / 60

$\leadsto$ 8 × 60 = n × ( 1.6 × 10-¹⁹)

$\leadsto$ 480 = n × ( 1.6 × 10-¹⁹ )

$\leadsto$ n = 480 / ( 1.6 × 10-¹⁹ )

$\leadsto$ n = 3 × 10²¹

3 × 10²¹ are the number of electrons pass through its cross - section in one minute

$\large{\boxed{\boxed{\boxed{\boxed{\sf{3 \: × \: 10^{21}}}}}}}$

Hope it's helpful

Thank you :)