CT0pt-1A ray of light is bent when it passes from water to air. This is an example of:A) Huygen's Principle B) Snell's LawC) The superposition principle D) The lens equationairwaterCT0pt -2.A man is looking in a mirror and he sees his face just filling the mirror.The man now moves back, away from the mirror, watching his reflection. As he moves back, he sees the image of his face..A) continues to just fill the mirrorB) becomes smaller than the frame of the mirrorC) become larger than the frame of the mirror.Hint: ManVirtual ImageCT0pt -3 A ray of light passes through 3 regions labeled I, II, and III, as shown. How do the indices of refraction of regions I and III compare?A) nI > nIIIB) nI < nIIIC) nI = nIIID) Impossible to tell.IIIIII40°25°25°35°CT0pt -4. A ray of light passes thru a sheet of glass which is thick at the bottom and thin at the top. Which way is the ray traveling after it has passed through the glass? A) bent toward the thin endB) undeviated (goes straight thru)C) bent toward the thick endair, n=1glass, n=1.5A)B)C)CT0pt -5. A light ray passes from air to glass (smaller n to largern) as shown. Which way does the ray travel in the glass?CT0pt -6.A light ray inside glass is totally internally reflected from an air-glass interface as shown.The air surrounding the glass is replaced with water. With the same light ray in the glass, the total internal reflection will now...A) definitely not occur.B) definitely occur.C) not enough information to knowair, n=1glass, n=1.5A)B)C)D)glassairCT0pt -7. A converging lens has a focal length f = 20cm when it is in air. The lens is made of glass with index of refraction nglass = 1.6. When the lens is placed in water (nwater = 1.33), the focal length of the lens is.. ..A) Unchanged. B) greater, f > 20 cm.C) smaller, f < 20cm, but still positive D) negative.CT0pt -8. A bundle of parallel rays approaches the eye and some of the rays enter the eye's pupil, as shown below. No other rays enter the eye. What does the eye see?A) A single point of light, surrounded by blackness. B) A uniformly illuminated wall of light, like a white wall.C) Many scattered points of light, like stars in the night sky.D) None of theseEyeCT0pt -9Two point sources of light are imaged onto a screen by a converging lens as shown. The images are labeled 1 and 2. A mask is used to cover up the left half of the lens, as shown. What happens to the images on the screen when the mask is inserted over the left half the lens?A) Image 1 vanishesB) Image 2 vanishesC) Something else happens.12screenmasklensCT0pt -10A converging lens focuses the light from a nearby point source onto an image, as shown. The "focal point" of a lens is the pointon the optic axis, one focal length f from the lens. Where is the focal point of this lens?A) between the lens and the imageB) at the imageC) further from the lens than the image.objectimageA) B) C)lensCT0pt -11.An object is placed is placed near a diverging lens, but the object is further from the lens than the absolute value of the focal length of the lens. The image formed is..A) Real B) Virtual C) there is no image.The magnitude of the image distance, compared to the object distance, is ...A) smaller. B) greater. Answers: The image is virtual and the image distance is smaller than the object distance. The only way to understand this is to draw a ray diagram:You get the same answers whether or not the object distance is further from the lens than the focal point.objectimageoptic axisCT0pt -11Is the image on a movie screen real or virtual?A) real B) virtualIs the image seen with a virtual reality headset real or virtual?A) real B) virtualAnswer: When the rays actually converge at a point in space (where you can put a screen to see the image) then the image is real. The image is Real. Answers: The image must be further than 25cm from the viewer's eye for the viewer to be able to focus on the image. Theimage is Virtual.Q0pt -12. An object is placed closer to a magnifying glass than thefocal length. What are the signs of the focal length f, the object distance do, and the image distance di?A) f > 0, do > 0, di < 0. B) f < 0, do > 0, di < 0.C) f > 0, do < 0, di > 0. D) f > 0, do > 0, di > 0.imageobjectimage(virtual!)optic axis|do||di|If do = 5cm, |di| = 15 cm, and the object height ho is 1cm, what is the image height hi ? A) 2cm B) 3cm C) 4cm D) None of these.CT0pt -13. A person who is "near-sighted", or myopic, cannot focus on faraway objects (objects at infinity) because the curvature of the person's eye-lens is too great. This causes parallel rays (from a distant point source) to bend too much and focus in front of the retina. The person sees a fuzzy patch of light rather than a sharppoint.This person needs eyeglasses with lenses that areA) converging B) divergingC) either converging or diverging, depending on much correction is needed.f (too short)CT0pt -14An object is near a mirror. The virtual image formed by the mirror is upright, is smaller than the object, and is nearer the mirror than the object as shown. Is the mirror B: concave or C: convex ?Hint: For a plane mirror, the (virtual) image is the same distance from the mirror as the object. Imagine bending the mirror. Do the reflected rays bend so the image gets further or closer to the mirror.mirrorimageobject(A)concave(B)convexobjectimageCT0pt -15What's wrong with that scene in 2001?A) Astronaut Dave Bowman can't read the screens on his console.B) He's not weightless.C) There's no thrust plume coming from his pod.D) The background stars are moving.Ch0pt -16.An astronomical refracting telescope has 3/4 of its objective lenscovered with a mask.The observer reports that, compared to the image with no mask, the image is A) unchanged. B) 3/4 covered. C) the same image, but 1/4 as bright.D) the same image but 1/16 as bright.Shorter focal length magnifying glass give bigger virtual image.Longer focal length lens produces larger real image.smaller angle, smaller imagebigger angle, bigger imagefar awayarrow far awayarrow small imagebig imagebig fsmall fCT0pt -17Are you here today, or did you leave for Spring Break early?A) I left for break early, so I get no points today. B) I'm here today, ready to be informed and collecting clicker points.C) I'm here today, I'm half asleep, but still ready to collect clicker points.(Hint: Don't vote A!)CT23-19 A spy satellite is moved to a lower orbit, so that it is closer to the ground.
View Full Document
Unlocking...