definition of slit width (1 Viewer)

[Akshara Patil]

So can someone clarify the definition of 'd' in the diffraction grating formula - some qs use it for the width of the slit, whereas others use it for the separation between slits?

 

[Thundermaster123]

I am pretty sure 'd' is the distance between the centre of one slit to the centre of the other slit

 

[Run hard@thehsc]

Yea thas right - act its both (edit)

 

[wizzkids]

Yes, the use of the same symbol "d" can be a bit confusing for students.
When we analyse the diffraction pattern produced by a single slit, then d is the symbol given to the width of the slit. As light passes through a single slit, it creates a single bright band accompanied by diffraction fringes on the left and right sides.
When we analyse the diffraction pattern produced by multiple slits (e.g. a diffraction grating), then d is the symbol given to the spacing between the slits. A diffraction grating creates an extended pattern of bright and dark fringes.