Hi guys we got a lab today and I have to answer a few questions... I want to make sure my answers are correct... Convex Lenses 1. How do we locate the principal axis? We locate the principal axis by directing a beam to the middle of the lens (what is this called? optical center?) perpendicular to the surface. (why does the beam not refract again?) 2. State three rules that describe the path that light takes through a Convex Lens. If you send a ray perpendicular to the principal axis through the lens it will refract passing through the focal point. If you send a ray passing through the focal point diagonally towards the lens it will become perpendicular. If you send a ray diagonally through the middle of the lens .. it will hit the focal point? lol I dont know the third one.... 3. Why is a convex lens called a converging lens? A convex lens is called a converging lens because if you send rays which are paralel to the principal axis towards the lens they will all refract passing through the focal point and converging towards it. Now there is another lab on Concave lenses, question 1 and 2 are the same but 3 asks why it is called a diverging lens....... Question 1 will be the same answer, but... I dont really get number 2.... Basically having trouble with the rules... any help would be appreciated.