11. What EM wave makes cellular phone communication possible? A microwaves C. visible light B. radio waves D. gamma rays 12. The reflection on smooth surfaces that tend to produce images is called A. diffused reflection B. regular reflection C. glossy reflection D. specular reflection 13. The image you see in a plane mirror called a image because it is not a real, physical object. A imaginary B. physical C. reflected D. virtual 14. Image of an object as seen in a plane mirror is A real and inverted B. Virtual and inverted C. virtual and upright D. real and upright 15. Diffuse reflection is produced by surfaces that tend to reflect light in all directions, A rough B. semi rough C. semi smooth D. smooth 16. Out of the following which one is diverging on negative lens? A. convex lens B. concave lens C. parabolic lens D. plane lens 17. The Principal axis is denoted by the letter a. f b. F c.p d. P​