A diffraction Grating has 1.26 × 10" rulings uniformly spaced over a width of 25.5 mm. It is illuminated at normal incidence by yellow light from a sodium vapor lamp. The light contains two very closely spaced emission lines (known as the sodium doublet) of wavelengths 589.00 nm and 589.59 nm. (a) At what angle the first order maximum occur (on either side of the central diffraction pattern) for the wavelength 589.00 nm? ( dsine = m2 ) (b) Use the dispersion of the grating D de - a0 calculate the angular YP separation between the two lines (sodium doublets) in the first order. (c) The diffraction pattern is observed on a screen 4.0 m behind the Grating. What is the linear separation of the two first order diffracted lines on the screen?

A diffraction Grating has 1.26 × 10" rulings uniformly spaced over a width of 25.5 mm. It is illuminated at normal incidence by yellow light from a sodium vapor lamp. The light contains two very closely spaced emission lines (known as the sodium doublet) of wavelengths 589.00 nm and 589.59 nm. (a) At what angle the first order maximum occur (on either side of the central diffraction pattern) for the wavelength 589.00 nm? ( dsine = m2 ) (b) Use the dispersion of the grating D de - a0 calculate the angular YP separation between the two lines (sodium doublets) in the first order. (c) The diffraction pattern is observed on a screen 4.0 m behind the Grating. What is the linear separation of the two first order diffracted lines on the screen?