SOME EFFECTS OF LIGHT 231 



QUESTIONS 



1. Explain the rainbow. 



2. What is a spectrum, and how is it produced? 



3. How do convex and concave lenses affect light-rays? 



4. What is the principle of a compound microscope and of a 



telescope ? 



5. How are photographs made? 



6. What relation does light hold to food production? 



7. Why are leaves green? 



