Answer:
1) Grating spacing, [tex]d = 1028.63 nm[/tex]
2a) [tex]\theta = 38.93^{0}[/tex]
2b) [tex]\theta = 27.89^{0}[/tex]
Explanation:
1) wavelength, [tex]\lambda = 590 nm[/tex]
the angle of overlap, [tex]\theta = 35.0^{0}[/tex]
Grating spacing, d = ?
Order of spectrum, m = 1
Diffraction condition for maximum intensity can be given by the relation:
[tex]d sin \theta = m \lambda[/tex]
[tex]d sin35 = 1 * 590 * 10^{-9} \\d = \frac{ 590 * 10^{-9}}{sin 35} \\d = 1028.63 nm[/tex]
2a) for the 646.3 nm line
[tex]\lambda = 646.3 nm[/tex]
d = 1028.63 nm
m =1
[tex]d sin \theta = m \lambda\\1028.63 sin \theta = 1 * 646.3\\sin \theta = \frac{646.3}{1028.63} \\sin \theta = 0.6283\\\theta = sin^{-1} 0.6283\\\theta = 38.93^{0}[/tex]
2b) for the 481.1 nm line
[tex]\lambda = 481.1 nm[/tex]
d = 1028.63 nm
m =1
[tex]d sin \theta = m \lambda\\1028.63 sin \theta = 1 * 481.1\\sin \theta = \frac{481.1}{1028.63} \\sin \theta = 0.4677\\\theta = sin^{-1} 0.4677\\\theta = 27.89^{0}[/tex]