# Lab Report on Diffraction | Physics Assignment Helpers

Objective

• To understand the diffraction of light using a red laser

Abstract

The detector angle 2ϴ records the diffraction peak position. This position of the diffraction peaks are determined by the distance between parallel planes of atoms. The x-ray wavelength of most diffractometer is fixed. Calculating the wavelength of a red laser, the following equation is used: Lambda = (a*x)/d, Lambda is the wavelength in meters, a is the distance between the slits, x is the fringe separation and D distance between the screen and the grating. The grating is known to have 500 lines per mm thus this means 500,000lines per m.1/500,000 to get distance between them 2µm. Now wavelength can be calculated using the above equation.

A= 0.00004 m,d = 0.00025m x= 2*10^-9 m

Wavelength= 0.00004*2*10^-9/0.00025

= 3.2*10-7m

Equipment

The equipment used were a laser beam and a diffractometer.

Data

 Peaks Position(x ,y) Peak separation 1 0.0720m, 0.478% 0.0121m 2 0.0743m, 1.02% 0.0098m 3 0.0767m, 1.69% 0.0074m 4 0,0792m, 2.40% 0.0049m 5 0.0818m, 2.85% 0.0023m 6 0.0841m, 3.03% 0.0000m 7 0.0866m,2.72% 0.0025m 8 0.0891m, 2.15% 0.0050m 9 0,0915m, 1.44% 0.0074m 10 0.0940m, 0.796% 0.0099m

Screenshots of coordinates.

Analysis

Wavelength calculations

Wavelength = a*X/d

A=0.04mm or o.00004m, d= 0.25 mm or 0.00025 m, x= 1/500,000= 2µm

0.00004*2µm/0.00025= 3.2*10^-7m

Wavelength = 3.2*10-7m

Percentage error= (calculated value- accepted value/ accepted value)*100

320nm-640nm/640nm)*100= 50%

Conclusion

From the data collected above there was a percentage error of the wavelength calculated, which was 50%.Looking at the calculations the measurements did not lie within the maximum and minimum bounds though they were consistent. Even with such unaccounted errors the representation of the actual wavelength was fair and demonstrated a good presentation of diffraction of red light.

When two speakers are put at opposite ends of a room. The two sound s waves travel through the air spreading out through the room in a spherical manner. These two waves interfere in such a way they produce loud sound in some locations and no sound in other locations. The loud sounds are as a result of compressions meeting compressions or rarefactions meeting rarefactions, and for the no sounds appear in locations where rarefaction of one wave meets compressions of another wave.