Two large parallel conducting plates are placed close to each other ,the inner surface of the two plates have surface charge densities `+sigma` and `-sigma` .The outer surfaces are without charge.The electric field has a magnitude of

Options

A. ``(sigma)/(epsi_(0))` in the region between the plates
B. ''`(sigma)/(epsi_(0))` in the region between the plates
C. 0
D. none of these

Explanation

To find the magnitude of the electric field between two large parallel conducting plates with surface charge densities of \( +\sigma \) and \( -\sigma \), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Configuration**:
- We have two large parallel conducting plates.
- The inner surface of one plate has a surface charge density of \( +\sigma \) and the other plate has a surface charge density of \( -\sigma \).
- The outer surfaces of the plates are uncharged.

2. **Electric Field due to a Single Infinite Plane Sheet**:
- The electric field \( E \) due to a single infinite plane sheet with surface charge density \( \sigma \) is given by:
\[ E = \frac{\sigma}{2\epsilon_0} \]
- The direction of the electric field is away from the positively charged plate and towards the negatively charged plate.

3. **Calculate the Electric Field Between the Plates**:
- For the positively charged plate with charge density \( +\sigma \):
- The electric field \( E_1 \) directed away from the plate is:
\[ E_1 = \frac{\sigma}{2\epsilon_0} \]
- For the negatively charged plate with charge density \( -\sigma \):
- The electric field \( E_2 \) directed towards the plate is:
\[ E_2 = \frac{\sigma}{2\epsilon_0} \]
- Since both electric fields are in the same direction (from the positive plate to the negative plate), we can add their magnitudes.

4. **Net Electric Field Between the Plates**:
- The net electric field \( E_{net} \) between the two plates is:
\[ E_{net} = E_1 + E_2 = \frac{\sigma}{2\epsilon_0} + \frac{\sigma}{2\epsilon_0} = \frac{\sigma}{\epsilon_0} \]

5. **Direction of the Electric Field**:
- The direction of the electric field is from the positively charged plate to the negatively charged plate.

### Final Answer:
The magnitude of the electric field between the two plates is:
\[ E = \frac{\sigma}{\epsilon_0} \]