Fringe width equal to 1 mm is observed in the interference pattern of biprism experiment. Then the distance of nearest bright fringe from the central bright fringe will be :

Options

A. 1 mm
B. 0.5 mm
C. 2 mm
D. 0.25 mm

Answer

To solve the problem, we need to understand the concept of fringe width in the context of the interference pattern produced by a biprism experiment.

### Step-by-Step Solution:

1. **Understanding Fringe Width**:
The fringe width (β) in an interference pattern is defined as the distance between two consecutive bright or dark fringes. In this case, we are given that the fringe width is 1 mm.

2. **Identifying the Central Bright Fringe**:
In an interference pattern, the central bright fringe is the one located at the center of the pattern, which is typically designated as the zeroth order fringe (m = 0).

3. **Finding the Nearest Bright Fringe**:
The nearest bright fringe to the central bright fringe is the first order bright fringe (m = 1). The distance from the central bright fringe to the first order bright fringe is equal to the fringe width (β).

4. **Calculating the Distance**:
Since the fringe width is given as 1 mm, the distance from the central bright fringe (m = 0) to the nearest bright fringe (m = 1) is simply:
\[ \text{Distance} = \beta = 1 \text{ mm} \]

5. **Conclusion**:
Therefore, the distance of the nearest bright fringe from the central bright fringe is 1 mm.

### Final Answer:
The distance of the nearest bright fringe from the central bright fringe is **1 mm**.