lab result

Result

Part:1

we setup the spectrometer as showing in figure1

after the light hitting the surface of the prism we observed that there are several wave lengths seeing on the screen which was blue, green and red which given in figure 2

part:2

we replace the prism with the grating figure 3

when the light hit the surface of the grating, we note that the grating diffracted the light into three wavelengths red, green and blue.

Part :3

By using the 600 lines/mm grating and Using the diffraction-grating equation,

Color	λ ref (nm)	λ exp (nm)	Y(cm)	X(cm)
Red	620	651	19	8.5
Green	5	538	19	6.5
purple	405	423	19	5

By using the 1200lines/mm grating

Color	λ ref (nm)	λ exp (nm)	Y(cm)	X(cm)
purple	405	416	19	12
Green	5	535	19	16
Red	620	641	19	23

Part 4

We found the number of gratings on a Colgate toothpaste box by using the red laser and the equation

g is the gratings , λ is the red wavelength , n =1

Gratings	λ ref (nm)	Y(cm)	X(cm)
1075	405	19	17