Question A.)

A beam of polarised light with intensity I₀ is incident on a series of 2 polarising sheets. The first polarising sheet is at an angle of to the initial polarisation of the beam. The second polarising sheet is at an angle of 90 to the initial polarisation of the beam. If the final intensity of the light is 0.086I₀, what is the angle? Put your answer in degrees and don't give units.

Question B.)

A pole of length 173 cm stands in a pool of water, such that the top of the pole is 46 cm above the water surface. Sunlight is incident on the pole at an angle of 33 degrees from the vertical. What is the length of the shadow of the pole at the bottom of the pool? Use a refractive index of 1.33 for water and 1 for air. Put your answer in cm and give units.

Question C.)

You are sitting at the bottom of a pool, a depth 116.4 cm below the surface, looking directly up. If the water has a refractive index of 1.33, what is the diameter of the circle above you for which you can view objects above the water? Put your answer in cm and give units.

Question D.)

Light is incident on the end of a fibre optic cable. The cable has an internal fibre of refractive index 1.51 and an external sheath of refractive index 1.4. What is the maximum angle of incidence of the incoming light on the end of the fibre that still allows total internal reflection? Put your answer in degrees and don't give units.

Question E.)

A beam of unpolarised light is transmitted through 4 polarising sheets. The angle between each successive sheet is 37.2 degrees. What percentage of the original beam intensity is transmitted through the final sheet?