Question

The number of electrons constituting one coulomb of charge :

• A. $6.25 \times 10^{18}$
• B. $1.6 \times 10^{-19}$
• C. $7.25 \times 10^{23}$
• D. $6.23 \times 10^{-23}$

Hint:

The fundamental charge of an electron is $1.6 \times 10^{-19}$ C. To find the number of electrons in a given charge, divide the total charge by the charge of one electron.

Answer 1

The Correct Option is A

Step 1: Recall the charge of a single electron.
The charge of a single electron ($e$) is approximately $1.602 \times 10^{-19}$ Coulombs (C). Step 2: Understand the relationship between total charge, number of electrons, and charge per electron.
The total charge ($Q$) is equal to the number of electrons ($n$) multiplied by the charge of a single electron ($e$). So, $Q = n \times e$. Step 3: Rearrange the formula to find the number of electrons.
To find the number of electrons ($n$), we can rearrange the formula as: $n = \frac{Q}{e}$ Step 4: Substitute the given values into the formula.
We are given that $Q = 1$ Coulomb (C) and $e = 1.602 \times 10^{-19}$ C. $n = \frac{1 \, \text{C}}{1.602 \times 10^{-19} \, \text{C}}$ Step 5: Calculate the number of electrons.
$n \approx 6.242 \times 10^{18}$ Rounding to two decimal places, this is approximately $6.25 \times 10^{18}$. Step 6: Compare with the given options.
(1) $6.25 \times 10^{18}$: This matches our calculated value.
(2) $1.6 \times 10^{-19}$: This is the magnitude of the charge of a single electron, not the number of electrons in one coulomb.
(3) $7.25 \times 10^{23}$: This value is incorrect.
(4) $6.23 \times 10^{-23}$: This value is incorrect.
(1) $6.25 \times 10^{18$}