How Do You Calculate the Angle in a Diffraction Grating Equation?

[ibysaiyan]

Diffracting grating?kinda confused?

Homework Statement

bits given:lamda(660nm) n=1,d=3.33, angle=?

Homework Equations

n(lambda)=dsin(theta)

The Attempt at a Solution

so from re-arranging the formula,etc i got this :6.66x^-7/3.33=sin(theta)
=>2x10^-7=sin(theta)
=>angle=1.14x10^-5(after inverse sin function) ? not sure if that's the answer =/

 

[The Bob]

With what you're given, the answer (in degrees) seems fine to me.

The Bob

 

[ibysaiyan]

k thanks a lot because some1 told me that i got my d wrong, =) which is not now

 

[ibysaiyan]

cant w8 to become astronomer =),need to work hard <.<,good stopped my gaming addiction.sorry if i wasnt allowed to type something out of context

 

[The Bob]

As d was stated in the question, I can't see how it can be wrong. Good luck with your studies.

The Bob

 

[Redbelly98]

d=3.33

What are the units for this value of d? 3.33 meters would be awfully large for a diffraction grating!

 

[ibysaiyan]

What are the units for this value of d? 3.33 meters would be awfully large for a diffraction grating!

in the question was given that a diffraction grating is marked as 300lines/mm
a)find distance between slits (which i got 3.33 from 1/0.3)

 

[ibysaiyan]

lol yea distance between slits 3.33m lol can't be hmm

 

[ibysaiyan]

is probably mm

 

[The Bob]

What are the units for this value of d? 3.33 meters would be awfully large for a diffraction grating!

I've been away from units for too long. Yer, Redbelly98 is right. If it is 3.33mm then the answer is wrong. I apologise for assuming it was a 'plug-in-the-values' question. What's your final answer?

The Bob

 

[ibysaiyan]

the answer i got is 3.33 for d .idk where i am messing things up.

 

[Redbelly98]

in the question was given that a diffraction grating is marked as 300lines/mm

That is the key here. In 1 mm, there are 300 lines. So each line must be ____?

 

[ibysaiyan]

That is the key here. In 1 mm, there are 300 lines. So each line must be ____?

hmm would it be: d=1/300000=3.33x10^-6

 

[Redbelly98]

If you include the correct units with that number, yes.

 

[ibysaiyan]

k,ty =)