Question

10^18 electrons move from point A to point B inside a metal wire in 4 seconds. What is the current passing through the wire?
​

Answer 1

10^(14) positive ions move from a point B towards point A in 1 milli second. ... A current of 1 mA is flowing through a copper wire. ... Show that one ampere is equivalent to flow of `6.25xx10^(-18.

Answer 2

$\Large{\boxed{\underline{\overline{\mathfrak{\star \: </p><p>QuEsTiOn :- \: \star}}}}}$

10^18 electrons move from point A to point B inside a metal wire in 4 seconds. What is the current passing through the wire?

$\huge\underline{\overline{\mid{\bold{\pink{ANSWER-}}\mid}}}$

$\red{\bigstar}$ Current [A]

$\huge\leadsto{\sf\purple{0.4\: A}}$

Now ,

$\Large{\underline{\underline{\bf{GiVen:-}}}}$

❥ 10¹⁸ electrons move from point A to point B inside a metal wire in 4 seconds.

❥ No. of Electrons = 10¹⁸

❥ Time = 4 second

$\Large{\underline{\underline{\bf{Find:-}}}}$

❥ What is the Current passing through the wire =?

$\Large{\underline{\underline{\bf{SoLuTion:-}}}}$

Here we go !

As we all know

$\: \: \: \: \: \large{ \bf{ \boxed{ \bold{ I = \dfrac{Q}{t} }}}}$

Where ,

Current = " I "

Charge = "Q "

Time = "T "

We know the Formula :+

$\red{\bigstar}$ Q = ne [W]

Where ,

Charge = " Q "

No. of Electrons = " n "

Charge on electron = " e "

Therefore '

$\\ { \bold{Q = {10}^{18} \times 1.6 \times {10}^{ - 19} \: \: [ \: \: e=1.6 \times {10}^{ - 19} ]}}$

$\\ { \bold{Q = 1.6 \times {10}^{ - 1} \: \:}}$

$\underline{\boxed{\textsf{Q= {\textbf{0.6 c}}}}} \qquad\qquad \bigg\lgroup\bold{Charge} \bigg\rgroup$

Now , Let's find out current simply by applying formula :-

$\\ { \bold{ I = \dfrac{Q}{t} }}$

$\\ { \bold{ I = \dfrac{0.16}{4} }}$

$\therefore\underline{\boxed{\textsf{I = {\textbf{0.4A}}}}} \qquad\qquad \bigg\lgroup\bold{Current} \bigg\rgroup$

$\Large{\underline{\underline{\bf{Additional \: Information:-}}}}$

✦ What is Current ?

↠ Current is the rate at which electrons flow past a point in a complete electrical circuit. At its most basic, current = flow.

↠ It expresses the quantity of electrons (sometimes called "electrical charge") flowing past a point in a circuit over a given time.

✦ How to calculate Current ?

↠ Current is usually denoted by the symbol I. Ohm's law relates the current flowing through a conductor to the voltage V and resistance R; that is, V = IR. An alternative statement of Ohm's law is I = V/R.

✦ What is the unit of Charge and Electric Current ?

↠Unit of electric charge is coulomb or C, unit of electric current is ampere or A.

Note :-

Ohms Law and Power

$\sf\underline{\purple{\:\:\: \: \: To\: Find \: the \: Voltage ( V ) :- \:\:\:}}$[ V = I x R ] V (volts) = I (amps) x R (Ω)

$\sf\underline{\pink{\:\:\: \: \: To\: Find \: the \: Current ( I ) :- \:\:\:}}$ [ I = V ÷ R ] I (amps) = V (volts) ÷ R (Ω)

$\sf\underline{\purple{\:\:\: \: \: To\: Find \: the \: Resistance (R ) :- \:\:\:}}$ [ R = V ÷ I ] R (Ω) = V (volts) ÷ I (amps)

$\sf\underline{\pink{\:\:\: \: \: To\: Find \: the \: Power ( P ) :- \:\:\:}}$ [ P = V x I ] P (watts) = V (volts) x I (amps)