need both ASAP

3. The incident material remains constant. How does the angle of refraction change as: (2 marks) a. The index of refraction of the second medium increases Airnt=1.0003RefractionIndicesof Water nr=1.33 ice nr=1.31 Acefone nr=1.36 b. The index of refraction of the second medium decreases Ethyl Alcoholnt =1,36 Flint Glass nt=1.57 Crown Glass nr=1.52 Ruby and Sapphire 4. What has a higher critical angle, crown glass or flint glass? (1 mark) nr=1.77 Diamona ni=2.42 Zircon nr=1.92 Opal n1=1.44 Azunite n=1.76