Monochromatic light of wavelength =650 nm passes through a diffraction grating w

Question

Monochromatic light of wavelength =650 nm passes through a diffraction grating with 600 lines/mm. The grating is placed initially in the center of the screen at zero distance. The screen is square with the side 10 cm. The distance D between the grating and the screeen is then increased.

A) Find the maximum D where one can see on the screen 5 diffraction maxima (m=0,±1,±2).
=> Here I'm lost I've found the d=1/600 (lines/mm)=1,67*10^-6 m and then the angles from eq. d*sin=m. For m=0 the =0, for m=±1 the =±22,9° and for m=±2 the angle is =±51,1°. Here I can't seem to find the distance D. Could you please help me?

B) Make a graph of the number of maxima visible on hte screen vs. D, with D between 0 and 20 cm.

Explanation / Answer

A). to be able to see 5 maximum, the angle that the screen covers must be 2*51.1 degrees. it mean that D*tan 51.5 = 10/2 so that D=4(cm). -------------------------------- B). to do this, calculate the half angle cover by the screen when D varies between 0 and 20cm. 10/2D = tan alpha. so that alpha range from infinitive to 14 degrees. --- then draw the graph by calculate the angle of diffraction maxima. m=1 22.9 m=2 .... m=3 .... -------------

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.