What will be the effect on fringe width if distance between screen and slit is decreased?

Hence, if the distance between the slits is reduced then the width of the fringes increases. In that case, fewer nodal regions are produced on the screen and the fringes will become wider but less in number.

How does the fringe width gets affected if the distance between slits and screen is increased?

d = distance between the slits. $\lambda $ = wavelength. $\left( a \right)$ When the screen is moved away from the plane of the slits the distance between the slits is increased from equation (1). Therefore if D is increased, and it is given that remaining parameters remain same so bandwidth (B.W) is increased.

What happens when you increase the distance between the screen and slits?

You can see that the distance between the fringes increases linearly with screen distance from the two slits. In the next plot I doubled the distance between the two slits: the previous formula predicts that the distance between the fringes will halve. And is what happens, indeed.

What is the spacing between the slits?

For diffraction to produce an observable pattern, the spacing of the slits must be comparable to the wavelength of the radiation. Visible light has a wavelength range from ~400 nm to ~700 nm. A typical diffraction grating for visible light with 300 grooves per mm has a slit spacing of (1/300)mm = 3 μm = 3000 nm.

What happens to the interference pattern if the photographic screen is brought closer to the slits?

As source slit is brought closer to double slit plane, S decreases, teh interference pattern gets less and less sharp.

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

More interference occurs when d is wider. The spacings between different fringes decreases as the distance between the slits increases because it is dependent on L. Increasing the wavelength of the light increases the spacing between different fringes since the spacing between different fringes is wavelength dependent.

What happens to width of the fringes on the interference fringes in a Young’s double slit experiment when the separation between the two slits is increased?

(f) When the widths of the two slits are increased, the fringes become brigther. However, width of each slit should be considerably smaller than the separation between the slits. When the slits becomes so wide that this condition is not satisfied, the interference pattern disappears.