Question

A steady current of 2 A is flowing through a conducting wire. The number of electrons flowing per second in it is:

• A. \( 1.25 \times 10^7 \)
• B. \( 1.25 \times 10^{19} \)
• C. \( 2.50 \times 10^{10} \)
• D. \( 0.125 \times 10^{25} \)
• E. \( 2.5 \times 10^{17} \)

Hint:

The number of electrons flowing in a current is given by \( N = \frac{I}{e} \), where \( e \) is the charge of one electron.

Answer 1

The Correct Option is B

Step 1: The current \( I \) is related to the charge \( q \) passing through a conductor by the equation: \[ I = \frac{q}{t} \] 
where: 
- \( I = 2 \, {A} \) is the current, 
- \( q \) is the charge, and 
- \( t \) is the time. 
The charge of one electron is \( e = 1.6 \times 10^{-19} \, {C} \). 
Step 2: The number of electrons \( N \) passing through the wire per second is given by: \[ N = \frac{I}{e} = \frac{2}{1.6 \times 10^{-19}} = 1.25 \times 10^{19} \] 
Thus, the number of electrons flowing per second is \( 1.25 \times 10^{19} \).