Physics Lab-11
Virtual Lab Source : http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/slits.html
Assessment Criterion – DCP
Research Question: How does the slit width vary the angle that is required for a maxima in
double slit diffraction?
Hypothesis: There will be an inverse relation between slit width and angle.
Independent variable: The slit width is the independent variable.
Dependent variable: The angle for maxima is the dependent variable.
Controlled Variables:
1. The wavelength is controlled at 500 nm.
2. The distance between the slits and the screen at 100 cm.
Results:
The raw data table is shown below.
a / μm θ / rad
1
0.536
2
0.253
3
0.167
4
0.125
5
0.100
6
0.083
7
0.071
8
0.063
This was plotted on a scatter graph.
Data Processing:
To linearize the data 1/a was plotted against ϴ.
The processed data table is shown below.
(1/a) /
θ / rad
(1/μm)
1
0.536
0.5
0.253
0.333333333 0.167
0.25
0.125
0.2
0.100
0.166666667 0.083
0.142857143 0.071
0.125
0.063
The scatter graph is shown below
Conclusion and Evaluation:
1
The hypothesis was correct as 𝑎 had a linear relation with 𝜃. The errors were not considered
since it was a virtual experiment.