Question

diffraction grating is used to measure the wavelength of monochromatic light, as shown in the diagram.

The spacing of the slits in the grating is 1.00 x 10-6m. The angle between the first order diffraction maxima is 60.0o.
What is the wavelength of the light?

1.  A. 287 nm

2.  B. 470 nm

3.  C. 574 nm

4.  D. 940 nm​

Answer 1

Answer:

8.65×10kipower--6

Explanation:

path difference=asintita

so,path difference=n×wavelength

thus, asintita/n

Answer 2

The wavelength of light is 4.  D. 940 nm​

• According to the question:

                 Spacing between the slits (y) = $1$x $10^{-6}$ m

                 Angle between the first order diffraction maxima is = 60 degrees

• Thus the wavelength is:

                y= λ / sin theta

                1 x $10^{-6}$ =  λ / $\frac{1}{2} \sqrt{3}$

              =0.866x $10^{-6}$ m

Therfore the closest option is option 4. D. 940 nm​