If the source of light used in a young's double slit experiment is changed from red to violet

Options

A. the fringes will become brighter
B. consecutive fringes will come closer
C. the intensity of minima will increase
D. the central bright fringe will become a dark fringe

Answer

To solve the question regarding the change in light source from red to violet in a Young's double slit experiment, we can follow these steps:

### Step 1: Understand the relationship between color and wavelength
- Red light has a longer wavelength compared to violet light. Specifically, the wavelength of red light is approximately 620-750 nm, while violet light is around 380-450 nm.

### Step 2: Recall the formula for fringe width
- The fringe width (β) in a Young's double slit experiment is given by the formula:
\[ \beta = \frac{\lambda D}{d} \]
where:
- \( \beta \) = fringe width
- \( \lambda \) = wavelength of the light
- \( D \) = distance from the slits to the screen
- \( d \) = distance between the slits

### Step 3: Analyze the effect of changing the wavelength
- When the light source is changed from red to violet, the wavelength (\( \lambda \)) decreases. Since \( D \) and \( d \) remain constant, the only variable affecting the fringe width is \( \lambda \).

### Step 4: Determine the impact on fringe width
- Since \( \lambda \) decreases (from red to violet), the fringe width \( \beta \) will also decrease. This means that the fringes will get closer together.

### Step 5: Conclusion
- Therefore, when the source of light is changed from red to violet, the fringes will become closer to each other.

### Final Answer:
The fringes will become closer to each other when the source of light is changed from red to violet.

---