Light Kit & accessories, White paper
Method:
Analysis
It can be seen that from the table, the light ray is bent towards the normal because the angle of incidence is greater than the refracted angle thus stating that the Perspex block is of a greater density than air. The graph above shows the angle used against the refracted angle. From the graph it can be seen that as the angle used increases the refractive angle is also increased.
The table above shows the angle of incidence multiplied by Sin to give a value, which was graphed. This was also the same for the Refractive angle. The graph is a straight-line graph shows. The slope of the graph is Y=0.642x-0.0228. Using 1over the slope of line of best fit the refractive index of the Perspex block can be calculated.
Let X = 1; Y= 0.642(1) - 0.0228 Y= 0.6192 Y= 1.61
So the Refractive index of the Perspex block is 1.61
Discussion:
Systematic errors:
Perspex block not consisting of pure material
Voltage on battery pack not correctly calibrated properly
Impurity in the globe and globes wire, reducing or distorting the light
Random errors:
Protractor not accurately placed along the normal
Damaged equipment.
Over usage of light, reducing the strength of the light beam
Improvements:
There are some possible improvements that could be made to improve the results and practical experiment. The equipment should be checked prior to the practical to reduce errors during the experiment. Also introducing more accurate results by recording the results ten times, instead of just one (extending the practical time), work out average and try the experiment with other Perspex blocks to determine the true refractive index of the Perspex block. Compare the results to other practicals that were conducted and compare views and data.
The Results:
It can be seen from the graph ‘Sinr Vs Sini’ the line of best fits’ slop is Y=0.642x-0.0228. Using the equation 1over the slope of line of best fit the refractive index of the Perspex block the refractive index was found to be, 1.61 making it mare dense than air and less dense than diamond. This is also proved that the Perspex block is denser than air because of the Incidence Vs Refraction table (refer analysis). In the table it can be seen that the angle of refraction is always less than the angle of incidence, thus stating that the light beam is bent towards the normal.
Conclusion: It can be seen that from the results, as the beam of light enters from air into the Perspex block the beam is bent towards the normal. This means that the Perspex block is denser than air
