Optics Answers

How far from a magnifying glass do you place an object to view it?

closer than than the focal length
distance equal to the focal length
greater than the focal length but less than twice the focal length
at twice the focal length

How many diopters are there for for a converging lens with a focal length of 0.4m?

−2.5
−0.4
+0.4
+2.5

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?

light incident in water at 40 dgrees
light incident in water at 55 dgrees
light incident in air at 40 dgrees
light incident in air at 55 dgrees

If the sun is 150 million km away from the earth, how long does it take sunlight to reach the earth?

0.5 s
1500 s
45 s
500 s

Where is the image located when an object is 60 cm from a convex mirror with a focal length of20 cm?

15 cm behind
30 cm behind
60 cm behind
15 cm in front

What type of image is formed when an object is placed at a distance of 1.5 focal lengths from a convex mirror?

erect and virtual
inverted and virtual
erect and real
inverted and real

The focal length of a curved mirror is -------- the radius of the spherical surface.

twice
equal to
half
one-quater

What type of mirror would you use to produce a magnified image of your face?

plane
concave
convex
diffuse