Geometrical Optics Questions and Answers

A X Select one O a B O b A B Which letter in the diagram below represents the virtual image of object X

Consider the lens shown below An object is placed at a position between F and 2F The image will be located Select one O a between the focal point F and the 2F point O b on the same side of the lens as the object O c beyond the 2F point O d between the focal point F and the lens defer 2F F F 2F

In the diagrams below ray A would reflect and follow the law of reflection Ray A Ray B On the other hand ray B would Select one O a refract Ob nonsense Ray B would reflect and would follow the law of reflection C not reflect at all O d not follow the law of reflection

0 An 8cm tall candle is placed 30cm from a converging mirror with a focal length of 10c a How much larger will the candle appear to be b Draw a ray diagram and describe the image 16 F

What happens to a white light when you look at it through diffraction glasses O it separates into distinct rays O it separates into colors O nothing happens O the light is blocked out

1 When light passes from a more optically dense medium into a less optically dense medium it will bend normal towards away from the

Images which are closer to the lens than the object are than the size of the object Select one O a same O b enlarged c diminished

images are located on the same side of the lens as the object that is by looking in one direction the observer can see both the image and the object Select one O a real O b virtual

A image can be projected onto a screen Select one a real Ob virtual

Virtual images formed by converging lenses are compared to the object Select one same diminished O b O c enlarged

When formed by a single lens a Select one O a O b real virtual image is always uprigh

When used individually a Select one O a diverging O b converging lens usually forms real images

Einstein started a bit of a controversy about 100 years ago when he published a paper about light s behavior Do you know how the scientific community accepts that light behaves today You can check the Theory tab on your LabPad if you would like to read up on the theory before answering a It s still up for debate b Particle c Both a wave and particle d A wave

Consider the diagram below showing a light ray reflecting off a plane mirror If angle C were 40 then the angle of incidence would be B C

To see his full height a boy that is 1 meter tall needs a mirror that is at least Select one Oa 0 50 m tall Ob 0 75 m tall O c O d depends on how far the mirror is from the boy 1 m tall Oe 0 33 m tall

4 5 points total The figure to the right shows a container with two liquid layers A light ray enters the top liquid from air and is refracted as it passes into the bottom liquid The index of refraction of the top liquid is 1 125 a 1 point Is the index of refraction of the second medium n greater than less than or equal to the index of refraction of the first medium n Explain your reasoning qualitatively 3 cm M 4 cm 4 cm n 1 125 3 cm b 1 5 points Determine the value of n Show your work Hint Recall that 3 4 5 triangles are special c 1 point Draw the initial ray in air Indicate the angles of incidence and refraction and be qualitatively accurate with their magnitudes Explain

The diagram below depicts a ray of light drawn in red approaching a planar surface Which one of the green rays is representative of the reflected ray A B C D E

When a bundle of light undergoes diffuse reflection each individual ray in the bundle of light rays fails to follow the law of reflection Select one O True O False

They say that in Snell s archive they found an optical scheme which depicted lens Real object an its real image The object and the image are of the same size and shape but longitudinally inverted and the longer line of the object lies on the optical axis of the lens The image and object both ar shown here The image can be on either left hand side or right hand side of object Focal length c the lens f Obejct 0 optics axis 0 O should be at a distance of 2f from the lens The lens should be on the right hand side of the object The lens is converging in nature Image The focal length of the lens is 2a where a is length of one square grid

On the diagram label p q f h and h Variables p 1 Calculate the focal length 10 20 30 40 Calculate the magnification 60 70 B 90 If the object is 1 5 cm tall calculate h

4 5 points total An object is placed 5 cm from a converging lens with a focal length of 3 cm a 1 5 points Complete the ray diagram below to determine the location of the image using at least two principal rays Summarize the characteristics of the image real virtual upright inverted larger smaller same size from your diagram Explain what these characteristics tell us about the signs of the image distance d and image height h b 1 point Calculate the height of the image hi and its distance from the center of the lens d Show your work and note whether your results are consistent with your diagram above c 0 5 points What is the magnification of the image both sign and value How does the magnification tell you about the characteristics of the image Show your work and explain d 1 5 points How could you move the object such that the magnification is 2 rather than the value you calculated above If this is not possible state so explicitly Explain

An object slanted at an angle of 45 is placed in front of a vertical plane mirror as shown Mirror Which of the following shows the appar ent position and orientation of the object s image 1 2 3 5 6 7 image image image image image image image

A divergent lens forms a virtual image 0 41 times the size of the object The distance between object and image is 34 cm P h f 9 f Scale 10 cm Find the distance of the focal point from the center of the lens Answer in units of cm Your response i

2 Solve for the angle of incidence in medium 1 adl mont moda lonac arii ofenol or cane noned astiqo Hoot beido o su od trigh art to sist Pince lens al e distance frech ed w opaholl Serratoles 20 all cor e eau n 1 66 erit quis8 8 n 1 iw W SAI DRIED

2 The speed of light in a clear plastic is 1 90 x plastic 2pts Find the critical angle for a light ray traveling from the glass into water 2pts ncrown glass 1 52 8c nwater 1 33 8 90

What strategy did astronomers use to achieve the incredible resolving power necessary to successfully image the event horizon of the black hole in galaxy M87 Select one a They built the world s largest infrared telescope in the high desert of Chile which was able to achieve sensitivities greater than any telescope in history b They linked together a global chain of radio telescopes achieving the resolving power of a radio dish nearly the size of Earth c They used a specially engineered metallic coating on the Hubble Space Telescope allowing optical sensitivities never before imaginable d They inserted a new detector into the world s largest optical telescope allowing for sensitive observations at quelenatho prouiquchy out of reach

5 A 5cm tall candle is 32 cm from a converging mirror The curvature of the mirror is 20 cm center of curvature is double focal length a Where is the image of the candle located 2pts b What is the magnification of the candle 2pts

part 1 of 2 A convergent lens has a focal length of 28 cm The object distance is 10 9 cm h 9 P Scale 10 cm Find the distance of the image from the center of the lens Answer in units of cm Answer in units of cm part 2 of 2

In the diagram below line m is parallel to line n Figure 2 is the image of Figure 1 after a reflection over line m Figure 3 is the image of Figure 2 after a reflection over line n Figure 1 m Figure 2 n Figure 3 Which single transformation would carry Figure 1 onto Figure 3

4 A lens with a center of curvature of 50 cm forms an image 45 cm behind it a Find the object distance do b Find the magnification c Describe the image d Make a ray diagram evapod a moil moletos do ns to ogami ant mengaib yan a wendently C

2 An object 5 cm tall is 12 cm from a concave mirror The focal point is at 20 cm a Find the image location b Find the magnification c Find the image height d Describe the image e Draw a ray diagram ammot mo eruleyma to sothes a miw enel A

4 An object represented by an arrow is placed in front of a mirror The diagram below shows the object the image and the location of the mirror plane but not the type of mirror Mirror Plane Object Image a Is this a concave mirror a convex mirror or a plane mirror Explain how you know based on the characteristics of the image b Complete the ray diagram above by sketching the shape of the mirror drawing at least two principal rays that show how the image is formed by the mirror and indicating where the focus

6 An object represented by an arrow is placed 6 cm from a diverging lens as shown in the diagram below At this location the object makes a virtual image that is 1 3 the size of the object Object a Determine the image distance d both sign and value Show your work and explain your reasoning b Determine the focal length of the lens Then complete the ray diagram by indicating the focus and drawing the two principal rays that show how the image is formed by the object Show your work and explain your reasoning

A 2 cm high object is in front of a thin lens he object distance is 21 cm and the image istance is 8 cm The image height is 1 0 761905 cm 2 5 25 cm 3 0 0119048 cm 4 84 cm

Refraction of Light Change of velocity Change of wavelength n V O f f O A1 f1 A2 f2 On n OXZYo 2 In the above figure where the speed of light c fx A which of the following relations is correct Each symbol has its significance Ny Ph

The reason why a lens can alter the direction of light is because of Optical density Reflection Refraction Obiective

A substance that cannot be is composed of number of that have the same in its Every element has a unique It indicates the total of the atom Normal atoms are so it is also the number of Atomic Number Element Name Every element has its own unique name Many element names are very Like many are based on other languages is named after khloros the Greek word for greenish yellow New names are approved by an 12 into simpler substances by that is each atom has the same ELEMENTS Mg Magnesium 24 305 in the You What element s neutral atom has 17 electrons means An element Every element is using a unique two letters The first letter is always and if there is a second letter it is Some are based on other languages Fe is of one or from the Latin ferrium Chemical Symbol Atomic mass is the mass of and in an atom are so small they do not add to the mass The mass is a because it is an average of the the Atomic Mass that have more or less which are atoms of How many neutrons are in a lithium atom

The 100 meter diameter Green Bank Telescope GBT is a radio telescope with an aperture efficiency of 35 at 90 GHz a Calculate the effective diameter in meters of the GBT at 90 GHz Write down and describe all steps

The mirror equation Select the Concave mirror Move the light bulb to 15 and the focal point to 10 15 Turn off all lines and turn on Show ruler Question How is position of the image related to the position of the object and the focal length of the mirror 1 Measure In this activity you will measure the relationships between several values do Distance between object and mirror f Distance between focal point and mirror d Distance between image and mirror 10 d What are the current values of each of these variables Note You can use the ruler to and d

A convergent lens has a focal length of 13 6 cm The object distance is 32 6 cm P h 9 Scale 10 cm Find the distance of the image from the center of the lens Answer in units of cm Answer in units of cm

with an hour of time to respond and you are free to take two attempts As we cover four chapters this time with 25 questions the questions are pretty much evenly distributed among the chapters except for Ch 22 as it will be covered in HW 4 as well Good luck everyone and as before you may consult any resources you may think of during this one hour time period You don t have to turn in any scratch work as most questions are conceptual Any concern Email me Ms D Question 25 The index of refraction for water is about 4 3 What happens to light when it travels from air to water Its speed increases to 4c 3 and its frequency decreases by a factor of 3 4 O Its speed decreases to 3c 4 and its frequency increases b 4 3 O Its speed decreases to 3c 4 and its wavelength increases by a factor of 4 3 Its speed decreases to 3c 4 and its wavelength decreases by a factor of 3 4 O 1 pts

O 55 O 35 O 65 8 45 M If 8 in the figure 55 how about 82 120 82 Mz

Problem 2 Derive the apparent depth formula him 7 hobj where him is the image depth hobi is the height of the image above the surface n is the index of refraction of the transmission material and n is the index of refraction of the incident material You should start with Snell s law and use the small angle approximation sin 0 tan 0 Include a drawing to support your answer

A real object is located to the left of a convergent lens The object s distance and image s distance from the lens and the lens focal length are shown in the figures 15 23 Which diagram correctly shows the image The convergent lens in this problem is a part of a lens system so the object in this problem may be either real or virtual Construct a ray diagram f0 1 2 15 8 4 15 23 0 15 fo 23 3 44 15 15 8 23 f 0 15 S

n object is 30 cm in front of a converging of focal length 10 cm The image is 1 real and the same size than the object 2 real and larger than the object 3 real and smaller than the object 4 virtual and smaller than the object 5 SUBMIT AD

For the ray diagrams below it is acceptable to use only two principal rays one that leaves the object parallel to the optical axis and one that reflects off the center of the mirror You are welcome to use all three for greater accuracy You should also mark the focal point and draw the object an arrow with its tail on the optical axis Be careful with your diagram making sure the rays are straight and reflect from the reflecting plane of the mirror Note that the grids in the diagrams below are 1 cm square Make all your objects 1 5 cm tall 7 4 5 points total An object is placed 5 cm from a diverging lens with a focal length of 3 cm a 1 5 points Complete the ray diagram below to determine the location of the image using at least two principal rays Summarize the characteristics of the image real virtual upright inverted larger smaller same size from your diagram Explain what these characteristics tell us about the signs of the image distance d and image height hi b 1 point Calculate the height of the image h and its distance from the center of the lens d Show your work and note whether your results are consistent with your diagram above c 0 5 points What is the magnification of the image both sign and value How does the magnification tell you about the characteristics of the image Show your work and explain d 1 5 points How could you move the object such that the magnification is 2 3 rather than the value you calculated above If this is not possible state so explicitly Explain

Problem 3 A fish is swimming 0 130 m below the surface of a pond and is being viewed by someone whose eyes are about 1 500 m above the surface of the pond You may assume that the person and fish are in line with each other a Determine the apparent distance of the fish as viewed by the person b Determine the apparent distance of the person s as viewed by the fish

The magnification of a convex mirror is 5 The object is 3 cm tall How tall is the image Is the image real or virtual Is the image on the left or right side of the mirror

27 is the image real or virtual Explain 3 Find the critical angle at which light is no longer transmitted into medium 2 28 You can done by placing your hand n 1 atrigiert or griaugam 1

5 Which statements are true regarding refraction Check all that apply Light bends away from the normal when entering a lower index of refraction Light bends towards the normal when entering a lower index of refraction Light bends towards the normal when entering a higher index of refraction Light bends away from the normal when entering a higher index of refraction