A cloth is rubbed with wool is found to have a negative charge of `4xx10^(-8)`C. The no. of electron transferred is:

Options

A. `1.5xx10^(11)`
B. `2.5xx10^(11)`
C. `3.5xx10^(11)`
D. `4.5xx10^(11)`

Explanation

To find the number of electrons transferred when a cloth is rubbed with wool and acquires a negative charge of \(4 \times 10^{-8}\) C, we can follow these steps:

### Step 1: Understand the relationship between charge and number of electrons
The charge \(q\) is related to the number of electrons \(n\) by the equation:
\[ q = n \cdot e \]
where \(e\) is the charge of a single electron, approximately \(1.6 \times 10^{-19}\) C.

### Step 2: Rearrange the formula to find the number of electrons
To find the number of electrons \(n\), we can rearrange the formula:
\[ n = \frac{q}{e} \]

### Step 3: Substitute the known values
We know:
- \(q = 4 \times 10^{-8} \, \text{C}\)
- \(e = 1.6 \times 10^{-19} \, \text{C}\)

Substituting these values into the equation gives:
\[ n = \frac{4 \times 10^{-8}}{1.6 \times 10^{-19}} \]

### Step 4: Perform the division
Calculating the division:
\[ n = \frac{4}{1.6} \times 10^{-8 + 19} = \frac{4}{1.6} \times 10^{11} \]
Calculating \( \frac{4}{1.6} \):
\[ \frac{4}{1.6} = 2.5 \]
Thus, we have:
\[ n = 2.5 \times 10^{11} \]

### Step 5: Conclusion
The number of electrons transferred is:
\[ n = 2.5 \times 10^{11} \]