1. A ray of light enters glass (index 1.570) from air at an incident angle of 25. Find the angles of refraction and of deviation. 2. A light ray is directed through air (index 1.000) at a 25 angle of incidence toward a parallel-sided glass plate (index 1.570) which is 6.35 mm thick. What will be the lateral displacement of the light ray as it again emerges into air? 3. Find the critical angle for a light ray traveling from glass (index 1.600) to air (index 1.000). 4. A single lens reflex camera having a focal length of 50.0 mm is focussed at an object 10 ft away. What is the image distance for that condition? and R 2 5. The two spherical surfaces of a thin biconvex lens have radii R, of 10.0 cm and 15.0 cm, respectively. If the refractive index of the glass is 1.600, what is the focal length of the lens?