A) Order of the first laser: 3, order of the second laser: 2
B) The overlap occurs at an angle of 
Explanation:
A)
The formula that gives the position of the maxima (bright fringes) for a diffraction grating is

where
d is spacing between the lines in the grating
is the angle of the maximum
m is the order of diffraction
is the wavelength of the light
For laser 1,

For laser 2,

where

Since the position of the maxima in the two cases overlaps, then the term
on the left is the same for the two cases, therefore we can write:

Therefore:


B)
In order to find the angle at which the overlap occurs, we use the 1st laser situation:

where:
N = 450 lines/mm = 450,000 lines/m is the number of lines per unit length, so the spacing between the lines is

is the order of the maximum
is the wavelength of the laser light
Solving for
, we find the angle of the maximum:

So the angle is

Learn more about diffraction:
brainly.com/question/3183125
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