Question

31. Number of electrons flowing through a circuit, if 1 Amp of current
flows through it for 10 sec, equals to :
(1) 625 * 1019
(2) 6.25 * 104
(3) 625 x 1018
(4) 62.5 * 1019
​

Answer 1

Current= Charge/Time

1= Charge/10

Charge = 10 C

By quantisation of charge,

Charge= ne

Where n= number of electrons, and e= charge on a single electron= 1.6x10^19

$10 = n \times 1.6 \times {10}^{ - 19}$

$n = \frac{10}{1.6 \times {10}^{ - 19} }$

$n = \frac{10 \times {10}^{19} }{1.6}$

$n = 6.25 \times {10}^{19}$

Answer 2

Answer:

The number of electrons flowing in 1 sec when 1 A current flows through wire are  $6.25$ x $10^{18}$ .

Explanation:

Given,

current = 1 Amp , time = 1 sec

we know that,

                    $current(I) = \frac{charge(Q)}{time(t)}$

               → $charge(Q) = current(I) * Time(t)$

               → Q = 1 Amp   x  1 sec  = 1 coulomb

Again, we know that,

              $Q = n e$   [n → Total number of electrons]  

           → 1 = n x (1.6 x $10^{-19$)   [e → One electron charge =1.6 x $10^{-19$ ]

           → $n = \frac{1}{1.6 * 10^{-19}}$

                   = $6.25$ x $10^{18}$

Therefore,the number of electrons flowing in 1 sec when 1 A current flows through wire are  $6.25$ x $10^{18}$ .