If a charge on the body is `1 nC`, then how many electrons are present on the body?

Options

A. `1.6xx10^(19)`
B. `6.25xx10^(9)`
C. `6.25xx10^(27)`
D. `6.25xx10^(28)`

Answer

To find out how many electrons are present on a body with a charge of `1 nC`, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Charge**:
The charge on the body is given as `1 nC` (nanocoulomb). We need to convert this to coulombs:
\[ 1 \text{ nC} = 1 \times 10^{-9} \text{ C} \]

2. **Know the Charge of One Electron**:
The charge of a single electron is approximately:
\[ E = 1.6 \times 10^{-19} \text{ C} \]

3. **Use the Formula for Charge**:
The total charge \( Q \) on the body can be expressed in terms of the number of excess electrons \( N \) and the charge of a single electron \( E \):
\[ Q = N \cdot E \]
Rearranging this formula to solve for \( N \):
\[ N = \frac{Q}{E} \]

4. **Substitute the Values**:
Now, we can substitute the values of \( Q \) and \( E \) into the formula:
\[ N = \frac{1 \times 10^{-9} \text{ C}}{1.6 \times 10^{-19} \text{ C}} \]

5. **Calculate \( N \)**:
Performing the division:
\[ N = \frac{1}{1.6} \times 10^{-9 + 19} = 0.625 \times 10^{10} \]
This simplifies to:
\[ N = 6.25 \times 10^{9} \]

6. **Conclusion**:
Therefore, the number of electrons present on the body is:
\[ N = 6.25 \times 10^{9} \text{ electrons} \]