Experiments are performed to compare the refractive indices of different materials.
In one experiment a light ray passes from air to material A and the angles of incidence and refraction are measured. The refractive index for air is 1. The graph below was drawn using the results of material A.
6.1 Define the term angle of incidence. (2)
6.2 Calculate the refractive index of material A using the data in the graph. (3)
6.3 Calculate the speed of the light through material A. (3)
6.4 If material A is replaced by material B, the angle of refraction is 31° when the angle of incidence is 40°.
6.4.1 Calculate the refractive index of material B. (4)
6.4.2 Redraw the graph of material A, and on the same set of axis, draw the graph you expect for material B. Label the graphs of material A and material B clearly. (2)
6.5 Total internal reflection occurs when a light ray passes from material A to material B. The critical angle of material A is 49°.
6.5.1 Which range of angles will make it possible for total internal reflection to occur? (2)
6.5.2 What OTHER condition is necessary for total internal reflection to take place? (2)
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