Answer to Question #51680 in Optics for samson

Question

11 What type of image is formed when an object is placed at a distance of 1.5 focal lengths from a convex mirror?
a. erect and virtual
b. inverted and virtual
c. erect and real
d. inverted and real

12 Where is the image located when an object is 60 cm from a convex mirror with a focal length of20 cm?
a. 15 cm behind
b. 30 cm behind
c. 60 cm behind
d. 15 cm in front

13. If the sun is 150 million km away from the earth, how long does it take sunlight to reach the earth
a. 0.5 s
b. 1500 s
c. 45 s
d. 500 s
14 The critical angle for total internal reflection at an air-water interface is approximately 48 degrees. In which of the following situations will total internal reflection occur?
a. light incident in water at 40 dgrees
b. light incident in water at 55 dgrees
c. light incident in air at 40 dgrees
d. light incident in air at 55 dgrees
15 How many diopters are there for for a converging lens with a focal length of 0.4m?

a. −2.5
b. −0.4
c. +0.4
d. +2.5