In Young's double slit experiment, if the source of light changes from orange to blue then :

Options

A. the central bright fringe will become a dark fringe.
B. the distance between consecutive fringes will decrease.
C. the distance between consecutive fringes will increase.
D. the intensity of the minima will increase

Answer

To solve the problem regarding the change in light source from orange to blue in Young's double slit experiment, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Experiment**:
In Young's double slit experiment, light passes through two closely spaced slits and creates an interference pattern on a screen. The pattern consists of bright and dark fringes.

2. **Identifying the Parameters**:
The key parameters in the experiment include:
- Wavelength of light (λ)
- Fringe width (β), which is the distance between consecutive bright or dark fringes.

3. **Fringe Width Formula**:
The formula for fringe width (β) is given by:
\[ \beta = \frac{d \cdot \lambda}{D} \]
where:
- \(d\) = distance between the slits
- \(D\) = distance from the slits to the screen
- \(λ\) = wavelength of the light used

4. **Effect of Changing Wavelength**:
When the source of light changes from orange to blue, the wavelength (λ) of the light decreases.
- Orange light has a longer wavelength compared to blue light.
- Therefore, when switching from orange to blue, we have \(λ_{blue} < λ_{orange}\).

5. **Impact on Fringe Width**:
Since fringe width (β) is directly proportional to the wavelength (λ):
- If λ decreases, then β also decreases.
- Thus, the distance between consecutive fringes will decrease when changing from orange to blue light.

6. **Conclusion**:
The correct conclusion is that the distance between consecutive fringes will decrease when the light source changes from orange to blue.

### Final Answer:
The distance between consecutive fringes will decrease.

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