Double Slit Experiment. and diffrac5on gra5ngs

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Double Slit Experiment. and diffrac5on gra5ngs"

Transcription

1 Double Slit Experiment and diffrac5on gra5ngs

2 Diffraction

3 Diffraction is normally taken to refer to various phenomena which occur when a wave encounters an obstacle. It is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings

4 Superposition, or Interference Another characteristic of a WAVE is the ability to undergo INTERFERENCE. There are TWO types. We call these waves IN PHASE. We call these waves OUT OF PHASE.

5 Interference applet

6 Double-Slit Experiment to illustrate wave nature of light

7 Thomas Young s Double Slit Interference Experiment Gave credibility to the theory that light is a wave Showed an interference pattern Measured the wavelength of the light

8

9 Young s Double Slit Experiment

10 Young s Double Slit Interference Pattern

11 Interference Fringes on a Screen applet

12 Conditions Chapter 15 for Interference of Light Waves

13 Diffraction The Central Maximum Suppose you had TWO sources each being allowed to emit a wave through a small opening or slit. The distance between the slits denoted by, d. The distance from the slit spacing to the screen is denoted by the letter, L. If two waves go through the slit and then proceed straight ahead to the screen, they both cover the SAME DISTANCE and thus will have constructive interference. Their amplitudes will build and leave a very bright intense spot on the screen. We call this the CENTRAL MAXIMUM.

14 Diffraction The Central Maximum Figure 1 Figure 2 Here is the pattern you will see. Notice in figure 2 that there are several bright spots and dark areas in between. The spot in the middle is the BRIGHTEST and thus the CENTRAL MAXIMUM. We call these spots FRINGES. Notice we have additional bright spots, yet the intensity is a bit less. We denote these additional bright spots as ORDERS. So the first bright spot on either side of the central maximum is called the FIRST ORDER BRIGHT FRINGE. Figure 1 represents the intensity of the orders as we move farther from the bright central maximum.

15 Diffraction Orders, m We use the letter, m, to represent the ORDER of the fringe from the bright central. Second Order Bright Fringe m = 2 First Order Bright Fringe m = 1 Central Maximum m = 0 First Order Bright Fringe m = 1 Second Order Bright Fringe m = 2 It is important to understand that we see these bright fringes as a result of CONSTRUCTIVE INTERFERENCE. So bright fringes are ordered m = 0,1,2,3.

16 Diffraction Bright Fringes The reason you see additional bright fringes is because the waves CONSTRUCTIVELY build. There is a difference, however, in the intensity as you saw in the previous slide. As you can see in the picture, the BLUE WAVE has to travel farther than the RED WAVE to reach the screen at the position shown. For the BLUE WAVE and the RED WAVE to build constructively they MUST be IN PHASE. Here is the question: HOW MUCH FARTHER DID THE BLUE WAVE HAVE TO TRAVEL SO THAT THEY BOTH HIT THE SCREEN IN PHASE?

17 Diffraction Path difference Notice that these 2 waves are IN PHASE. When they hit they screen they both hit at the same relative position, at the bottom of a crest. λ How much farther did the red wave have to travel?

18 Diffraction Path difference Notice that these 2 waves are IN PHASE. When they hit they screen they both hit at the same relative position, at the bottom of a crest. λ How much farther did the red wave have to travel? ONE WAVELENGTH

19 Diffraction Path difference Notice that these 2 waves are IN PHASE. When they hit they screen they both hit at the same relative position, at the bottom of a crest. λ How much farther did the red wave have to travel? ONE WAVELENGTH We call this extra distance the PATH DIFFERENCE. The path difference and the ORDER of a fringe help to form a pattern.

20 Diffraction Path Difference 2λ 1λ 1λ 2λ The bright fringes you see on either side of the central maximum are multiple wavelengths from the bright central. And it just so happens that the multiple is the ORDER. Therefore, the PATH DIFFERENCE is equal to the ORDER times the WAVELENGTH P.D. = mλ (Constructive)

21 Diffraction Dark Fringes We see a definite DECREASE in intensity between the bright fringes. In the pattern we visibly notice the DARK REGION. These are areas where DESTRUCTIVE INTERFERENCE has occurred. We call these areas DARK FRINGES or MINIMUMS (minima).

22 Diffraction Dark Fringes First Order Dark Fringe m = 1 ZERO Order Dark Fringe m = 0 ZERO Order Dark Fringe m = 0 First Order Dark Fringe m = 1 It is important to understand that we see these dark fringes as a result of DESTRUCTIVE INTERFERENCE. So dark fringes are ordered m = 0,1,2,3.

23 Diffraction Dark Fringes On either side of the bright central maximum we see areas that are dark, or minimum intensity. Once again, we notice that the BLUE WAVE had to travel farther than the RED WAVE to reach the screen. At this point, however, they are said to destructively build or that they are OUT OF PHASE. Here is the question: HOW MUCH FARTHER DID THE BLUE WAVE HAVE TO TRAVEL SO THAT THEY BOTH HIT THE SCREEN OUT OF PHASE?

24 Diffraction Path difference Notice that these 2 waves are OUT OF PHASE. When they hit they screen they both hit at the different relative positions, one at the bottom of a crest and the other coming out of a trough. Thus their amplitudes SUBTRACT. 0.5 λ How much farther did the red wave have to travel?

25 Diffraction Path difference Notice that these 2 waves are OUT OF PHASE. When they hit they screen they both hit at the different relative positions, one at the bottom of a crest and the other coming out of a trough. Thus their amplitudes SUBTRACT. 0.5 λ How much farther did the red wave have to travel? ONE HALF OF A WAVELENGTH

26 Diffraction Path difference Notice that these 2 waves are OUT OF PHASE. When they hit they screen they both hit at the different relative positions, one at the bottom of a crest and the other coming out of a trough. Thus their amplitudes SUBTRACT. 0.5 λ How much farther did the red wave have to travel? ONE HALF OF A WAVELENGTH The call this extra distance the PATH DIFFERENCE. The path difference and the ORDER of a fringe help to form another pattern.

27 Diffraction Path Difference 1.5λ 1.5λ 0.5λ 0.5λ The dark fringes you see on either side of the central maximum are multiple wavelengths from the bright central. And it just so happens that the multiple is the ORDER. Therefore, the PATH DIFFERENCE is equal to the ORDER plus a HALF, times A WAVELENGTH P.D. = (m+1/2)λ (Destructive)

28 Path Difference - Summary For CONSTRUCTIVE INTERFERENCE or MAXIMA use: P.D. = mλ Where m = 0, 1, 2, 3 For DESTRUCTIVE INTERFERENCE or MINIMA use: P.D. = (m + 1/2) λ Where m, is the ORDER. Where m = 0, 1, 2, 3

29 d Young s Experiment In 1801, Thomas Young successfully showed that light does produce an interference pattern. This famous experiment PROVES that light has WAVE PROPERTIES. Suppose we have 2 slits separated by a distance, d and a distance L from a screen. Let point P be a bright fringe. θ P y central max We see in the figure that we can make a right triangle using, L, and y, which is the distance a fringe is from the bright central. We will use an angle, θ, from the point in the middle of the two slits. L We can find this angle using tangent!

30 Similar Triangles (or more often, y )

31 Diffraction Another way to look at path difference P This right triangle is SIMILAR to the one made by y & L. θ d θ central max d P.D. P.D. = dsinθ P.D. Notice the blue wave travels farther. The difference in distance is the path difference.

32 (Note that for a large distance, L, from the screen, ray 1 and ray 2 are approximately parallel).

33 Similar Triangles lead to a path difference y θ These angles Are EQUAL. L d dsinθ θ

34 sinθ = opp/hyp = path length difference / d So path length difference = d sinθ

35 Diffraction Putting it all together Path difference is equal to the following: mλ for constructive interference (m+1/2)λ for destructive interference dsinθ for both Therefore, we can say: Constructive Interference dsinθ = mλ Will be used to find the angle!

36 Similar Triangles (or more often, y ) Notice: tan θ = y / L

37 Example #1 A viewing screen is separated from a double slit source by 1.2 m. The distance between the two slits is mm. The second -order bright fringe ( m=2) is 4.5 cm from the central maximum. Determine the wavelength of light.

38 Example #1 A viewing screen is separated from a double slit source by 1.2 m. The distance between the two slits is mm. The second -order bright fringe ( m=2) is 4.5 cm from the central maximum. Determine the wavelength of light degrees dsinθ = mλ (3x10 5 )sin(2.15) = 2λ λ = 5.62x10-7 m

39 Small Angle Approximation When L is large, the hypotenuse is very close in value to L If θ is small (less than a few deg), we can say that sinθ tanθ

40 L d sinθ = mλ m = 0,1,2,3... Maximum d sinθ d tanθ = dy L = mλ also, tanθ = y m L so for maxima, or y m = mλl d Maxima y m = Ltanθ Lsinθ Minima m y m (+/-) m y m (+/-) Lλ/d 2Lλ/d 3Lλ/d Lλ/2d 3Lλ/2d 5Lλ/2d 7Lλ/2d (or P.D.) & for minima, = d sinθ dsinθ = (m + 1 )λ m = 0,1,2,3... Minimum 2 y m = (m +1/2)λL d

41 EXAMPLE #2 Suppose that Young s experiment is performed with blue-green light of 500 nm. The slits are 1.2 mm apart, and the viewing screen is 5.4 m from the slits. How far apart are the bright fringes?

42 EXAMPLE #2 Suppose that Young s experiment is performed with blue-green light of 500 nm. The slits are 1.2 mm apart, and the viewing screen is 5.4 m from the slits. How far apart are the bright fringes? From the table on the previous slide we see that the separation between bright fringes is Δy =

43 EXAMPLE #2 Suppose that Young s experiment is performed with blue-green light of 500 nm. The slits are 1.2 mm apart, and the viewing screen is 5.4 m from the slits. How far apart are the bright fringes? From the table on the previous slide we see that the separation between bright fringes is Δy = Lλ /d

44 EXAMPLE #2 Suppose that Young s experiment is performed with blue-green light of 500 nm. The slits are 1.2 mm apart, and the viewing screen is 5.4 m from the slits. How far apart are the bright fringes? From the table on the previous slide we see that the separation between bright fringes is Δy = Lλ /d Lλ /d = (5.4m)( m) /0.0012m

45 EXAMPLE #2 Suppose that Young s experiment is performed with blue-green light of 500 nm. The slits are 1.2 mm apart, and the viewing screen is 5.4 m from the slits. How far apart are the bright fringes? From the table on the previous slide we see that the separation between bright fringes is Δy = Lλ /d Lλ /d = (5.4m)( m) /0.0012m = m = 2.25mm

46

47 A diffraction grating that consists of a large number of parallel slits overcomes both of these difficulties. A diffraction grating uses interference to disperse light. It is often an important component in optical instrumentation for wavelength determinations.

48

49 For a diffraction grating, the intensity falls away from these maxima much more rapidly than that for a double slit. Because there are so many slits to act as sources, any angle other than those for maxima will be dark or nearly dark.

50 Diffraction gratings A diffraction grating is a precise array of tiny engraved lines, each of which allows light through. The spectrum produced is a mixture of many different wavelengths of light.

51 How a Diffraction Grating Works When you look at a diffracted light you see: the light straight ahead as if the grating were transparent. a "central bright spot". the interference of all other light waves from many different grooves produces a scattered pattern called a spectrum.

52 Note: We cannot use the small angle approximation for diffraction gratings. For gratings, since d is very small, to observe some of the higher order fringes, we usually have to place the screen very close to the grating; therefore, the angle θ is no longer small.

53 The Diffraction Grating Diffraction grating is an arrangement consisting of a large number of parallel, closely spaced slits. Gratings with as many as slits per centimeter can be made, depending on the production method. In one method a diamond-tipped cutting tool is used to inscribe closely spaced parallel lines on a glass plate, the spaces between the lines serving as the slits.

54 Double Slit & Grating The bright fringes produced by a diffraction grating are much narrower than those produced by a double slit. Note the three small secondary bright fringes between the principal bright fringes of the grating. For a large number of slits, these secondary fringes become very small.

55 Grating Formula wavelength of light (nm) distance between grating lines (m) mλ = d sinθ constructive d sinθ = (m )λ destructive Note: sometimes the given data for slit separation is given as lines per _ meters instead of d Set 1/d = number of lines per m (NOTE: a line is the solid material separating each slit).

56 Double Slit & Grating The bright fringes produced by a diffraction grating are much narrower than those produced by a double slit. Note the three small secondary bright fringes between the principal bright fringes of the grating. For a large number of slits, these secondary fringes become very small.

57 Example #3 A light with wavelength, 450 nm, falls on a diffraction grating (multiple slits). On a screen 1.80 m away the distance between dark fringes on either side of the bright central is 4.20 mm. a) What is the separation between a set of slits? b) How many lines per meter are on the grating?

58 Example #3 A light with wavelength, 450 nm, falls on a diffraction grating (multiple slits). On a screen 1.80 m away the distance between dark fringes on either side of the bright central is 4.20 mm. a) What is the separation between a set of slits? b) How many lines per meter are on the grating? NOTE: a line is the solid material separating each slit.

59 Example #3 A light with wavelength, 450 nm, falls on a diffraction grating (multiple slits). On a screen 1.80 m away, the distance between dark fringes on either side of the bright central is 4.20 mm. a) What is the separation between a set of slits? b) How many lines per meter are on the grating? NOTE: a line is the solid material separating each slit. λ = 450x10 9 m L =1.80m y = 4.2mm /2 = m θ =? d =? degrees lines/m m

Interference. Physics 102 Workshop #3. General Instructions

Interference. Physics 102 Workshop #3. General Instructions Interference Physics 102 Workshop #3 Name: Lab Partner(s): Instructor: Time of Workshop: General Instructions Workshop exercises are to be carried out in groups of three. One report per group is due by

More information

6) How wide must a narrow slit be if the first diffraction minimum occurs at ±12 with laser light of 633 nm?

6) How wide must a narrow slit be if the first diffraction minimum occurs at ±12 with laser light of 633 nm? Test IV Name 1) In a single slit diffraction experiment, the width of the slit is 3.1 10-5 m and the distance from the slit to the screen is 2.2 m. If the beam of light of wavelength 600 nm passes through

More information

AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light

AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light Name: Period: Date: MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Reflection,

More information

Answer: b. Answer: a. Answer: d

Answer: b. Answer: a. Answer: d Practice Test IV Name 1) In a single slit diffraction experiment, the width of the slit is 3.1 10-5 m and the distance from the slit to the screen is 2.2 m. If the beam of light of wavelength 600 nm passes

More information

Physics 10. Lecture 29A. "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton

Physics 10. Lecture 29A. There are two ways of spreading light: to be the candle or the mirror that reflects it. --Edith Wharton Physics 10 Lecture 29A "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton Converging Lenses What if we wanted to use refraction to converge parallel

More information

INTERFERENCE OBJECTIVES PRE-LECTURE. Aims

INTERFERENCE OBJECTIVES PRE-LECTURE. Aims 53 L4 INTERFERENCE Aims OBJECTIVES When you have finished this chapter you should understand how the wave model of light can be used to explain the phenomenon of interference. You should be able to describe

More information

Lecture 12: Fraunhofer diffraction by a single slit

Lecture 12: Fraunhofer diffraction by a single slit Lecture 12: Fraunhofer diffraction y a single slit Lecture aims to explain: 1. Diffraction prolem asics (reminder) 2. Calculation of the diffraction integral for a long slit 3. Diffraction pattern produced

More information

Light, Light Bulbs and the Electromagnetic Spectrum

Light, Light Bulbs and the Electromagnetic Spectrum Light, Light Bulbs and the Electromagnetic Spectrum Spectrum The different wavelengths of electromagnetic waves present in visible light correspond to what we see as different colours. Electromagnetic

More information

Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect

Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect Objectives: PS-7.1 Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect Illustrate ways that the energy of waves is transferred by interaction with

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A single slit forms a diffraction pattern, with the first minimum at an angle of 40 from

More information

ILLUSTRATIVE EXAMPLE: Given: A = 3 and B = 4 if we now want the value of C=? C = 3 + 4 = 9 + 16 = 25 or 2

ILLUSTRATIVE EXAMPLE: Given: A = 3 and B = 4 if we now want the value of C=? C = 3 + 4 = 9 + 16 = 25 or 2 Forensic Spectral Anaylysis: Warm up! The study of triangles has been done since ancient times. Many of the early discoveries about triangles are still used today. We will only be concerned with the "right

More information

ATOMIC SPECTRA. Apparatus: Optical spectrometer, spectral tubes, power supply, incandescent lamp, bottles of dyed water, elevating jack or block.

ATOMIC SPECTRA. Apparatus: Optical spectrometer, spectral tubes, power supply, incandescent lamp, bottles of dyed water, elevating jack or block. 1 ATOMIC SPECTRA Objective: To measure the wavelengths of visible light emitted by atomic hydrogen and verify the measured wavelengths against those predicted by quantum theory. To identify an unknown

More information

Diffraction of Laser Light

Diffraction of Laser Light Diffraction of Laser Light No Prelab Introduction The laser is a unique light source because its light is coherent and monochromatic. Coherent light is made up of waves, which are all in phase. Monochromatic

More information

Periodic Wave Phenomena

Periodic Wave Phenomena Name: Periodic Wave Phenomena 1. The diagram shows radar waves being emitted from a stationary police car and reflected by a moving car back to the police car. The difference in apparent frequency between

More information

Chapter 23. The Refraction of Light: Lenses and Optical Instruments

Chapter 23. The Refraction of Light: Lenses and Optical Instruments Chapter 23 The Refraction of Light: Lenses and Optical Instruments Lenses Converging and diverging lenses. Lenses refract light in such a way that an image of the light source is formed. With a converging

More information

Measure the Distance Between Tracks of CD and DVD

Measure the Distance Between Tracks of CD and DVD University of Technology Laser & Optoelectronics Engineering Department Laser Eng Branch Laser application Lab. The aim of work: Experiment (9) Measure the Distance Between Tracks of CD and DVD 1-measure

More information

Waves Sound and Light

Waves Sound and Light Waves Sound and Light r2 c:\files\courses\1710\spr12\wavetrans.doc Ron Robertson The Nature of Waves Waves are a type of energy transmission that results from a periodic disturbance (vibration). They are

More information

Diffraction and Young s Single Slit Experiment

Diffraction and Young s Single Slit Experiment Diffraction and Young s Single Slit Experiment Developers AB Overby Objectives Preparation Background The objectives of this experiment are to observe Fraunhofer, or far-field, diffraction through a single

More information

Physics 111 Homework Solutions Week #9 - Tuesday

Physics 111 Homework Solutions Week #9 - Tuesday Physics 111 Homework Solutions Week #9 - Tuesday Friday, February 25, 2011 Chapter 22 Questions - None Multiple-Choice 223 A 224 C 225 B 226 B 227 B 229 D Problems 227 In this double slit experiment we

More information

WHITE LIGHT AND COLORED LIGHT

WHITE LIGHT AND COLORED LIGHT grades K 5 Objective This activity offers two simple ways to demonstrate that white light is made of different colors of light mixed together. The first uses special glasses to reveal the colors that make

More information

Solution Derivations for Capa #14

Solution Derivations for Capa #14 Solution Derivations for Capa #4 ) An image of the moon is focused onto a screen using a converging lens of focal length (f = 34.8 cm). The diameter of the moon is 3.48 0 6 m, and its mean distance from

More information

- the. or may. scales on. Butterfly wing. magnified about 75 times.

- the. or may. scales on. Butterfly wing. magnified about 75 times. Lecture Notes (Applications of Diffraction) Intro: - the iridescent colors seen in many beetles is due to diffraction of light rays hitting the small groovess of its exoskeleton - these ridges are only

More information

Interference and Diffraction

Interference and Diffraction Chapter 14 nterference and Diffraction 14.1 Superposition of Waves... 14-14. Young s Double-Slit Experiment... 14-4 Example 14.1: Double-Slit Experiment... 14-7 14.3 ntensity Distribution... 14-8 Example

More information

PHYS 222 Spring 2012 Final Exam. Closed books, notes, etc. No electronic device except a calculator.

PHYS 222 Spring 2012 Final Exam. Closed books, notes, etc. No electronic device except a calculator. PHYS 222 Spring 2012 Final Exam Closed books, notes, etc. No electronic device except a calculator. NAME: (all questions with equal weight) 1. If the distance between two point charges is tripled, the

More information

4.4 WAVE CHARACTERISTICS 4.5 WAVE PROPERTIES HW/Study Packet

4.4 WAVE CHARACTERISTICS 4.5 WAVE PROPERTIES HW/Study Packet 4.4 WAVE CHARACTERISTICS 4.5 WAVE PROPERTIES HW/Study Packet Required: READ Hamper pp 115-134 SL/HL Supplemental: Cutnell and Johnson, pp 473-477, 507-513 Tsokos, pp 216-242 REMEMBER TO. Work through all

More information

PHY208FALL2008. Week2HW. Introduction to Two-Source Interference. Due at 11:59pm on Friday, September 12, View Grading Details [ Print ]

PHY208FALL2008. Week2HW. Introduction to Two-Source Interference. Due at 11:59pm on Friday, September 12, View Grading Details [ Print ] Assignment Display Mode: View Printable Answers PHY208FALL2008 Week2HW Due at 11:59pm on Friday September 12 2008 View Grading Details [ Print ] The following three problems concern interference from two

More information

Study Guide for Exam on Light

Study Guide for Exam on Light Name: Class: Date: Study Guide for Exam on Light Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which portion of the electromagnetic spectrum is used

More information

Fraunhofer Diffraction

Fraunhofer Diffraction Physics 334 Spring 1 Purpose Fraunhofer Diffraction The experiment will test the theory of Fraunhofer diffraction at a single slit by comparing a careful measurement of the angular dependence of intensity

More information

Processes affecting propagation of electromagnetic radiation (light)

Processes affecting propagation of electromagnetic radiation (light) Chapter 4 Light and Color, and Atmospheric Optics Useful links: http://www.atoptics.co.uk/ http://www.gi.alaska.edu/atmossci/links.mainpage/arcti c_optical.html Processes affecting propagation of electromagnetic

More information

EXPERIMENT O-6. Michelson Interferometer. Abstract. References. Pre-Lab

EXPERIMENT O-6. Michelson Interferometer. Abstract. References. Pre-Lab EXPERIMENT O-6 Michelson Interferometer Abstract A Michelson interferometer, constructed by the student, is used to measure the wavelength of He-Ne laser light and the index of refraction of a flat transparent

More information

DIFFRACTION AND INTERFERENCE

DIFFRACTION AND INTERFERENCE DIFFRACTION AND INTERFERENCE In this experiment you will emonstrate the wave nature of light by investigating how it bens aroun eges an how it interferes constructively an estructively. You will observe

More information

Refraction of Light at a Plane Surface. Object: To study the refraction of light from water into air, at a plane surface.

Refraction of Light at a Plane Surface. Object: To study the refraction of light from water into air, at a plane surface. Refraction of Light at a Plane Surface Object: To study the refraction of light from water into air, at a plane surface. Apparatus: Refraction tank, 6.3 V power supply. Theory: The travel of light waves

More information

Question based on Refraction and Refractive index. Glass Slab, Lateral Shift.

Question based on Refraction and Refractive index. Glass Slab, Lateral Shift. Question based on Refraction and Refractive index. Glass Slab, Lateral Shift. Q.What is refraction of light? What are the laws of refraction? Ans: Deviation of ray of light from its original path when

More information

Experiment #12: The Bohr Atom. Equipment: Spectroscope Hydrogen and Helium Gas Discharge Tubes, Holder, and Variac Flashlight

Experiment #12: The Bohr Atom. Equipment: Spectroscope Hydrogen and Helium Gas Discharge Tubes, Holder, and Variac Flashlight Experiment #12: The Bohr Atom Purpose: To observe the visible spectrum of hydrogen and helium and verify the Bohr model of the hydrogen atom. Equipment: Spectroscope Hydrogen and Helium Gas Discharge Tubes,

More information

What s so special about the laser?

What s so special about the laser? What s so special about the laser? A guide for taking LaserFest into the classroom. Developed by 2010 SPS SOCK interns Patrick Haddox & Jasdeep Maggo. www.spsnational.org Activity 1: Exploring laser light

More information

Using lasers to shed light on musical sound

Using lasers to shed light on musical sound Using lasers to shed light on musical sound By: Talon Holmes and Aaron Zaubi PHY 312 Introduction Ever since the invention of the laser, scientists have been trying to find ways to utilize them to help

More information

3.5.4.2 One example: Michelson interferometer

3.5.4.2 One example: Michelson interferometer 3.5.4.2 One example: Michelson interferometer mirror 1 mirror 2 light source 1 2 3 beam splitter 4 object (n object ) interference pattern we either observe fringes of same thickness (parallel light) or

More information

GEOMETRICAL OPTICS. Lens Prism Mirror

GEOMETRICAL OPTICS. Lens Prism Mirror GEOMETRICAL OPTICS Geometrical optics is the treatment of the passage of light through lenses, prisms, etc. by representing the light as rays. A light ray from a source goes in a straight line through

More information

Physics 41 Chapter 38 HW Key

Physics 41 Chapter 38 HW Key Physics 41 Chapter 38 HW Key 1. Helium neon laser light (63..8 nm) is sent through a 0.300-mm-wide single slit. What is the width of the central imum on a screen 1.00 m from the slit? 7 6.38 10 sin θ.11

More information

How is LASER light different from white light? Teacher Notes

How is LASER light different from white light? Teacher Notes How is LASER light different from white light? Teacher Notes Concepts: (1) Light is a type of energy that travels as waves. [6.2.3.1.1] (2) Laser light is different from traditional light sources and must

More information

Theremino System Theremino Spectrometer Technology

Theremino System Theremino Spectrometer Technology Theremino System Theremino Spectrometer Technology theremino System - Theremino Spectrometer Technology - August 15, 2014 - Page 1 Operation principles By placing a digital camera with a diffraction grating

More information

GRID AND PRISM SPECTROMETERS

GRID AND PRISM SPECTROMETERS FYSA230/2 GRID AND PRISM SPECTROMETERS 1. Introduction Electromagnetic radiation (e.g. visible light) experiences reflection, refraction, interference and diffraction phenomena when entering and passing

More information

9.3. Diffraction and Interference of Water Waves

9.3. Diffraction and Interference of Water Waves Diffraction an Interference of Water Waves 9.3 Have you ever notice how people relaxing at the seashore spen so much of their time watching the ocean waves moving over the water, as they break repeately

More information

Waves and Light Extra Study Questions

Waves and Light Extra Study Questions Waves and Light Extra Study Questions Short Answer 1. Determine the frequency for each of the following. (a) A bouncing spring completes 10 vibrations in 7.6 s. (b) An atom vibrates 2.5 10 10 times in

More information

Rutgers Analytical Physics 750:228, Spring 2016 ( RUPHY228S16 )

Rutgers Analytical Physics 750:228, Spring 2016 ( RUPHY228S16 ) 1 of 13 2/17/2016 5:28 PM Signed in as Weida Wu, Instructor Help Sign Out Rutgers Analytical Physics 750:228, Spring 2016 ( RUPHY228S16 ) My Courses Course Settings University Physics with Modern Physics,

More information

P R E A M B L E. Facilitated workshop problems for class discussion (1.5 hours)

P R E A M B L E. Facilitated workshop problems for class discussion (1.5 hours) INSURANCE SCAM OPTICS - LABORATORY INVESTIGATION P R E A M B L E The original form of the problem is an Experimental Group Research Project, undertaken by students organised into small groups working as

More information

STOP for science. Light is a wave. Like waves in water, it can be characterized by a wavelength.

STOP for science. Light is a wave. Like waves in water, it can be characterized by a wavelength. INTRODUCTION Most students have encountered rainbows, either spotting them directly on those special days when the raindrops fall while the Sun still finds cloudless regions to peek through, or at least

More information

LAUE DIFFRACTION INTRODUCTION CHARACTERISTICS X RAYS BREMSSTRAHLUNG

LAUE DIFFRACTION INTRODUCTION CHARACTERISTICS X RAYS BREMSSTRAHLUNG LAUE DIFFRACTION INTRODUCTION X-rays are electromagnetic radiations that originate outside the nucleus. There are two major processes for X-ray production which are quite different and which lead to different

More information

v = fλ PROGRESSIVE WAVES 1 Candidates should be able to :

v = fλ PROGRESSIVE WAVES 1 Candidates should be able to : PROGRESSIVE WAVES 1 Candidates should be able to : Describe and distinguish between progressive longitudinal and transverse waves. With the exception of electromagnetic waves, which do not need a material

More information

Laser Viewing Tank P2-7690

Laser Viewing Tank P2-7690 WWW.ARBORSCI.COM Laser Viewing Tank P2-7690 BACKGROUND: Exploring basic optical phenomena with s is highly engaging and more cost-effective than ever before. But beams, themselves, are invisible. Classroom

More information

Chapter 17: Light and Image Formation

Chapter 17: Light and Image Formation Chapter 17: Light and Image Formation 1. When light enters a medium with a higher index of refraction it is A. absorbed. B. bent away from the normal. C. bent towards from the normal. D. continues in the

More information

The Electromagnetic Spectrum

The Electromagnetic Spectrum The Electromagnetic Spectrum 1 Look around you. What do you see? You might say "people, desks, and papers." What you really see is light bouncing off people, desks, and papers. You can only see objects

More information

The Nature of Electromagnetic Radiation

The Nature of Electromagnetic Radiation II The Nature of Electromagnetic Radiation The Sun s energy has traveled across space as electromagnetic radiation, and that is the form in which it arrives on Earth. It is this radiation that determines

More information

WAVELENGTH OF LIGHT - DIFFRACTION GRATING

WAVELENGTH OF LIGHT - DIFFRACTION GRATING PURPOSE In this experiment we will use the diffraction grating and the spectrometer to measure wavelengths in the mercury spectrum. THEORY A diffraction grating is essentially a series of parallel equidistant

More information

Basic Physical Optics

Basic Physical Optics F UNDAMENTALS OF PHOTONICS Module 1.4 Basic Physical Optics Leno S. Pedrotti CORD Waco, Texas In Module 1-3, Basic Geometrical Optics, we made use of light rays to demonstrate reflection and refraction

More information

Friday 18 January 2013 Morning

Friday 18 January 2013 Morning Friday 18 January 2013 Morning AS GCE PHYSICS B (ADVANCING PHYSICS) G492/01 Understanding Processes / Experimentation and Data Handling *G411640113* Candidates answer on the Question Paper. OCR supplied

More information

RESOLVING POWER OF A READING TELESCOPE

RESOLVING POWER OF A READING TELESCOPE 96 Lab Experiments Experiment-255 RESOLVING POWER OF A READING TELESCOPE S Dr Jeethendra Kumar P K KamalJeeth Instrumentation & Service Unit, No-60, TATA Nagar, Bangalore-560 092, INDIA. Email:jeeth_kjisu@rediffmail.com

More information

THE BOHR QUANTUM MODEL

THE BOHR QUANTUM MODEL THE BOHR QUANTUM MODEL INTRODUCTION When light from a low-pressure gas is subject to an electric discharge, a discrete line spectrum is emitted. When light from such a low-pressure gas is examined with

More information

INTERFERENCE OF SOUND WAVES

INTERFERENCE OF SOUND WAVES 1/2016 Sound 1/8 INTERFERENCE OF SOUND WAVES PURPOSE: To measure the wavelength, frequency, and propagation speed of ultrasonic sound waves and to observe interference phenomena with ultrasonic sound waves.

More information

Table 1 r (m) I (W/m 2 ) 0.10 477.46 0.20 119.37 0.50 19.10 1.00 4.77 2.00 1.19 5.00 0.19 10.00 0.05 Table 2: Intensities at 1-m Distances Power (W)

Table 1 r (m) I (W/m 2 ) 0.10 477.46 0.20 119.37 0.50 19.10 1.00 4.77 2.00 1.19 5.00 0.19 10.00 0.05 Table 2: Intensities at 1-m Distances Power (W) Light Intensity The term intensity is used to describe the rate at which light spreads over a surface of a given area some distance from a source. The intensity varies with the distance from the source

More information

Alignement of a ring cavity laser

Alignement of a ring cavity laser Alignement of a ring cavity laser 1 Introduction This manual describes a procedure to align the cavity of our Ti:Sapphire ring laser and its injection with an Argon-Ion pump laser beam. The setup is shown

More information

Using light scattering method to find The surface tension of water

Using light scattering method to find The surface tension of water Experiment (8) Using light scattering method to find The surface tension of water The aim of work: The goals of this experiment are to confirm the relationship between angular frequency and wave vector

More information

Automatic and Objective Measurement of Residual Stress and Cord in Glass

Automatic and Objective Measurement of Residual Stress and Cord in Glass Automatic and Objective Measurement of Residual Stress and Cord in Glass GlassTrend - ICG TC15/21 Seminar SENSORS AND PROCESS CONTROL 13-14 October 2015, Eindhoven Henning Katte, ilis gmbh copyright ilis

More information

Swing Curves and the Process Window

Swing Curves and the Process Window T h e L i t h o g r a p h y E x p e r t (Winter 1998) Swing Curves and the Process Window Chris A. Mack, FINLE Technologies, Austin, Texas As we saw in the last edition of The Lithography Expert, numerical

More information

Electromagnetic Radiation Wave and Particle Models of Light

Electromagnetic Radiation Wave and Particle Models of Light Electromagnetic Radiation 2007 26 minutes Teacher Notes: Victoria Millar BSc (Hons), Dip. Ed, MSc Program Synopsis For hundreds of years, scientists have hypothesised about the structure of light. Two

More information

1 Laboratory #5: Grating Spectrometer

1 Laboratory #5: Grating Spectrometer SIMG-215-20061: LABORATORY #5 1 Laboratory #5: Grating Spectrometer 1.1 Objective: To observe and measure the spectra of different light sources. 1.2 Materials: 1. OSA optics kit. 2. Nikon digital camera

More information

USING CDs AND DVDs AS DIFFRACTION GRATINGS

USING CDs AND DVDs AS DIFFRACTION GRATINGS USING CDs AND DVDs AS DIFFRACTION GRATINGS Rama Balachandran Riverwood High School Atlanta, GA Karen Porter-Davis Chamblee Charter High School Chamblee, GA Copyright Georgia Institute of Technology 2009

More information

3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted

3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted Light and Sound 3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted 3.15 use the law of reflection (the angle of incidence equals the angle of reflection)

More information

Note it they ancients had known Newton s first law, the retrograde motion of the planets would have told them that the Earth was moving.

Note it they ancients had known Newton s first law, the retrograde motion of the planets would have told them that the Earth was moving. 6/24 Discussion of the first law. The first law appears to be contained within the second and it is. Why state it? Newton s laws are not always valid they are not valid in, say, an accelerating automobile.

More information

88 CHAPTER 2. VECTOR FUNCTIONS. . First, we need to compute T (s). a By definition, r (s) T (s) = 1 a sin s a. sin s a, cos s a

88 CHAPTER 2. VECTOR FUNCTIONS. . First, we need to compute T (s). a By definition, r (s) T (s) = 1 a sin s a. sin s a, cos s a 88 CHAPTER. VECTOR FUNCTIONS.4 Curvature.4.1 Definitions and Examples The notion of curvature measures how sharply a curve bends. We would expect the curvature to be 0 for a straight line, to be very small

More information

INTERFERENCE OF SOUND WAVES

INTERFERENCE OF SOUND WAVES 2011 Interference - 1 INTERFERENCE OF SOUND WAVES The objectives of this experiment are: To measure the wavelength, frequency, and propagation speed of ultrasonic sound waves. To observe interference phenomena

More information

Light and Spectra. COLOR λ, nm COLOR λ, nm violet 405 yellow 579 blue 436 orange 623 green 492 red 689

Light and Spectra. COLOR λ, nm COLOR λ, nm violet 405 yellow 579 blue 436 orange 623 green 492 red 689 Light and Spectra INTRODUCTION Light and color have intrigued humans since antiquity. In this experiment, you will consider several aspects of light including: a. The visible spectrum of colors (red to

More information

PhysFest March Holography

PhysFest March Holography PhysFest March 2013 Holography Holography (from the Greek, holos whole + graphe writing) is the science of producing holograms, an advanced form of photography that allows an image to be recorded in three

More information

Physics Open House. Faraday's Law and EM Waves Change in the magnetic field strength in coils generates a current. Electromagnetic Radiation

Physics Open House. Faraday's Law and EM Waves Change in the magnetic field strength in coils generates a current. Electromagnetic Radiation Electromagnetic Radiation (How we get most of our information about the cosmos) Examples of electromagnetic radiation: Light Infrared Ultraviolet Microwaves AM radio FM radio TV signals Cell phone signals

More information

Crystal Optics of Visible Light

Crystal Optics of Visible Light Crystal Optics of Visible Light This can be a very helpful aspect of minerals in understanding the petrographic history of a rock. The manner by which light is transferred through a mineral is a means

More information

Investigating electromagnetic radiation

Investigating electromagnetic radiation Investigating electromagnetic radiation Announcements: First midterm is 7:30pm on 2/17/09 Problem solving sessions M3-5 and T3-4,5-6. Homework due at 12:50pm on Wednesday. We are covering Chapter 4 this

More information

Conceptual Physics Review (Chapters 25, 26, 27 & 28) Chapter 25 Describe the period of a pendulum. Describe the characteristics and properties of

Conceptual Physics Review (Chapters 25, 26, 27 & 28) Chapter 25 Describe the period of a pendulum. Describe the characteristics and properties of Conceptual Physics Review (Chapters 25, 26, 27 & 28) Solutions Chapter 25 Describe the period of a pendulum. Describe the characteristics and properties of waves. Describe wave motion. Describe factors

More information

Representing Vector Fields Using Field Line Diagrams

Representing Vector Fields Using Field Line Diagrams Minds On Physics Activity FFá2 5 Representing Vector Fields Using Field Line Diagrams Purpose and Expected Outcome One way of representing vector fields is using arrows to indicate the strength and direction

More information

Standing Waves and the Velocity of Sound

Standing Waves and the Velocity of Sound Chapter 8 Standing Waves and the Velocity of Sound 8.1 Purpose In this experiment we will be using resonance points of a sound wave traveling through an open tube to measure the speed of sound in air.

More information

PHYSICS PAPER 1 (THEORY)

PHYSICS PAPER 1 (THEORY) PHYSICS PAPER 1 (THEORY) (Three hours) (Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.) ---------------------------------------------------------------------------------------------------------------------

More information

Teaching Time: Two 50-minute periods

Teaching Time: Two 50-minute periods Lesson Summary In this lesson, students will build an open spectrograph to calculate the angle the light is transmitted through a holographic diffraction grating. After finding the desired angles, the

More information

Optical Interferometers

Optical Interferometers Optical Interferometers Experiment objectives: Assemble and align Michelson and Fabry-Perot interferometers, calibrate them using a laser of known wavelength, and then use them characterize the bright

More information

1051-232 Imaging Systems Laboratory II. Laboratory 4: Basic Lens Design in OSLO April 2 & 4, 2002

1051-232 Imaging Systems Laboratory II. Laboratory 4: Basic Lens Design in OSLO April 2 & 4, 2002 05-232 Imaging Systems Laboratory II Laboratory 4: Basic Lens Design in OSLO April 2 & 4, 2002 Abstract: For designing the optics of an imaging system, one of the main types of tools used today is optical

More information

Wake pattern of a boat

Wake pattern of a boat UNIVERSITY OF LJUBLJANA FACULTY OF MATHEMATICS AND PHYSICS DEPARTMENT OF PHYSICS Seminar 2008/09 Wake pattern of a boat Špela Rožman mentor: doc. dr. Aleš Mohorič Ljubljana, 13. 5. 2009 Summary A ship

More information

Review Vocabulary spectrum: a range of values or properties

Review Vocabulary spectrum: a range of values or properties Standards 7.3.19: Explain that human eyes respond to a narrow range of wavelengths of the electromagnetic spectrum. 7.3.20: Describe that something can be seen when light waves emitted or reflected by

More information

Physics 1230: Light and Color

Physics 1230: Light and Color Physics 1230: Light and Color Exam 1 is tomorrow, Wed. June 9, in class. Covers material from Chapter 1, pgs 1-25, Lectures and Homework 1-3. HW4 will be up soon. Due Thursday, 5PM Lecture 5: Shadows,

More information

Basic Quantum Mechanics Prof. Ajoy Ghatak Department of Physics. Indian Institute of Technology, Delhi

Basic Quantum Mechanics Prof. Ajoy Ghatak Department of Physics. Indian Institute of Technology, Delhi Basic Quantum Mechanics Prof. Ajoy Ghatak Department of Physics. Indian Institute of Technology, Delhi Module No. # 02 Simple Solutions of the 1 Dimensional Schrodinger Equation Lecture No. # 7. The Free

More information

Interferometers. OBJECTIVES To examine the operation of several kinds of interferometers. d sin = n (1)

Interferometers. OBJECTIVES To examine the operation of several kinds of interferometers. d sin = n (1) Interferometers The true worth of an experimenter consists in his pursuing not only what he seeks in his experiment, but also what he did not seek. Claude Bernard (1813-1878) OBJECTIVES To examine the

More information

Diffraction of a Circular Aperture

Diffraction of a Circular Aperture Diffraction of a Circular Aperture Diffraction can be understood by considering the wave nature of light. Huygen's principle, illustrated in the image below, states that each point on a propagating wavefront

More information

Thomson and Rayleigh Scattering

Thomson and Rayleigh Scattering Thomson and Rayleigh Scattering Initial questions: What produces the shapes of emission and absorption lines? What information can we get from them regarding the environment or other conditions? In this

More information

X-Ray Diffraction. wavelength Electric field of light

X-Ray Diffraction. wavelength Electric field of light Light is composed of electromagnetic radiation with an electric component that modulates versus time perpendicular to the direction it is travelling (the magnetic component is also perpendicular to the

More information

Measuring index of refraction

Measuring index of refraction Grzegorz F. Wojewoda Zespół Szkół Ogólnokształcących nr 1 Bydgoszcz, Poland Logo designed by Armella Leung, www.armella.fr.to Translation: Małgorzata Czart Measuring index of refraction The advent of low-cost

More information

After a wave passes through a medium, how does the position of that medium compare to its original position?

After a wave passes through a medium, how does the position of that medium compare to its original position? Light Waves Test Question Bank Standard/Advanced Name: Question 1 (1 point) The electromagnetic waves with the highest frequencies are called A. radio waves. B. gamma rays. C. X-rays. D. visible light.

More information

Astronomy 114 Summary of Important Concepts #1 1

Astronomy 114 Summary of Important Concepts #1 1 Astronomy 114 Summary of Important Concepts #1 1 1 Kepler s Third Law Kepler discovered that the size of a planet s orbit (the semi-major axis of the ellipse) is simply related to sidereal period of the

More information

Resonance and the Speed of Sound

Resonance and the Speed of Sound Name: Partner(s): Date: Resonance and the Speed of Sound 1. Purpose Sound is a common type of mechanical wave that can be heard but not seen. In today s lab, you will investigate the nature of sound waves

More information

PRACTICE EXAM IV P202 SPRING 2004

PRACTICE EXAM IV P202 SPRING 2004 PRACTICE EXAM IV P202 SPRING 2004 1. In two separate double slit experiments, an interference pattern is observed on a screen. In the first experiment, violet light (λ = 754 nm) is used and a second-order

More information

Grade 8 Science Chapter 4 Notes

Grade 8 Science Chapter 4 Notes Grade 8 Science Chapter 4 Notes Optics the science that deals with the properties of light. Light a form of energy that can be detected by the human eye. The History of Optics (3 Scientists): 1. Pythagoras

More information

FTIR Instrumentation

FTIR Instrumentation FTIR Instrumentation Adopted from the FTIR lab instruction by H.-N. Hsieh, New Jersey Institute of Technology: http://www-ec.njit.edu/~hsieh/ene669/ftir.html 1. IR Instrumentation Two types of instrumentation

More information

O6: The Diffraction Grating Spectrometer

O6: The Diffraction Grating Spectrometer 2B30: PRACTICAL ASTROPHYSICS FORMAL REPORT: O6: The Diffraction Grating Spectrometer Adam Hill Lab partner: G. Evans Tutor: Dr. Peter Storey 1 Abstract The calibration of a diffraction grating spectrometer

More information

LIGHT SECTION 6-REFRACTION-BENDING LIGHT From Hands on Science by Linda Poore, 2003.

LIGHT SECTION 6-REFRACTION-BENDING LIGHT From Hands on Science by Linda Poore, 2003. LIGHT SECTION 6-REFRACTION-BENDING LIGHT From Hands on Science by Linda Poore, 2003. STANDARDS: Students know an object is seen when light traveling from an object enters our eye. Students will differentiate

More information