I with my physics lab questions about diffraction grafting

[kreb11]

question
1) If "d" is the grafting constant "spacing between 2 slits on a grating), hwo can we obtain the ruling (number of grooves per meter) "D"?

2) Illistrate order of diffraction

 

[sophiecentaur]

1. Did you read the "Do NOT POST HOMEWORK" notice at the top of this forum.
2. It's a 'grating constant'. "Grafting" is what gardeners do with fruit trees.
3. Isn't this in your notes? How is 'number per unit length' related to 'spacing'? Imagine it was a row of fence posts.