Question

How does the fringe spacing change when the distance between the slits $D$ is increased?

Answer 1

Explanation:

The fringe spacing is called the bandwidth. The bandwidth is given by the formula

$\beta =\frac{\lambda D}{d}$

$\mathit{\lambda }$ is the wavelength of the light

$D$ is the distance between the source and the screen

$d$ is the distance between the two slits

From the formula, we understand if the distance between the source and the screen is increased then the fringe spacing increases.

Knows that as $d$ becomes longer, the distance between different fringes decreases. This is consistent with the observation that $d$ has an inverse relationship with the distances between different fringes.

1. As the slit separation $d$ increases, the separation of the interference fringes decreases. If the slit spacing is significant compared to the slit diameter, the diffraction pattern will be visible from the two slits.
2. Know that fringe width is equal to wavelength multiplied by the distance from the screen to slit divided by the separation of two-slit

$\beta =\frac{\lambda D}{d}$

3. We observe that $\beta$ and $d$ are inversely related, and $\beta$ and $D$ are directly related.

4. Here, the relationship between the fringing width and the slit separation is inverse; as a result, as the fringing width increases, the slit separation decreases.