In p-n junction, having depletion layer of thickness `2 ×10^(-6)m` the potential difference across it is 0.2 V. The electric field is

Options

A. `10^6V/m`
B. `4×10^5V/m`
C. `10^5V/m`
D. `10^(-5)V/m`

Answer

To find the electric field (E) across a p-n junction depletion layer, we can use the formula:

\[ E = \frac{V}{L} \]

where:
- \( V \) is the potential difference across the depletion layer,
- \( L \) is the thickness of the depletion layer.

### Step-by-Step Solution:

1. **Identify the Given Values**:
- Potential difference (\( V \)) = 0.2 V
- Thickness of the depletion layer (\( L \)) = \( 2 \times 10^{-6} \) m

2. **Substitute the Values into the Formula**:
\[ E = \frac{0.2 \, \text{V}}{2 \times 10^{-6} \, \text{m}} \]

3. **Calculate the Electric Field**:
- First, calculate the denominator:
\[ 2 \times 10^{-6} = 0.000002 \, \text{m} \]
- Now perform the division:
\[ E = \frac{0.2}{2 \times 10^{-6}} = \frac{0.2}{0.000002} = 100000 \, \text{V/m} \]

4. **Express the Result in Scientific Notation**:
\[ E = 1 \times 10^{5} \, \text{V/m} \]

### Final Answer:
The electric field across the depletion layer is \( 1 \times 10^{5} \, \text{V/m} \).

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