I am a high school student replicating the Faraday Effect. I plan to insert a clear liquid, such as distilled water, into a container that will be located inside of solenoid. I plan on using a test tube, however, I have doubts on whether or not the curved bottom of a test tube will alter the transition of light when it travels inside of the solenoid. Above is an apparatus that is a very close approximation of my experiment. I plan to insert the test tube inside of the solenoid, held together by clay or an applicable substance that can hold the tube in place. Will the tube provide accurate rotation of the light regardless of its curved surface, and if not, is there another alternative I can use?