DP Physics Questionbank

Description

Nature of science:
Curiosity: Observed patterns of iridescence in animals, such as the shimmer of peacock feathers, led scientists to develop the theory of thin film interference. (1.5)
Serendipity: The first laboratory production of thin films was accidental. (1.5)

Understandings:

• Young’s double-slit experiment
• Modulation of two-slit interference pattern by one-slit diffraction effect
• Multiple slit and diffraction grating interference patterns
• Thin film interference

Applications and skills:

• Qualitatively describing two-slit interference patterns, including modulation by one-slit diffraction effect
• Investigating Young’s double-slit experimentally
• Sketching and interpreting intensity graphs of double-slit interference patterns
• Solving problems involving the diffraction grating equation
• Describing conditions necessary for constructive and destructive interference from thin films, including phase change at interface and effect of refractive index
• Solving problems involving interference from thin films

Guidance:

• Students should be introduced to interference patterns from a variety of coherent sources such as (but not limited to) electromagnetic waves, sound and simulated demonstrations
• Diffraction grating patterns are restricted to those formed at normal incidence
• The treatment of thin film interference is confined to parallel-sided films at normal incidence
• The constructive interference and destructive interference formulae listed below and in the data booklet apply to specific cases of phase changes at interfaces and are not generally true

Data booklet reference:

Theory of knowledge:

• Most two-slit interference descriptions can be made without reference to the one-slit modulation effect. To what level can scientists ignore parts of a model for simplicity and clarity?

Utilization:

• Compact discs are a commercial example of the use of diffraction gratings
• Thin films are used to produce anti-reflection coatings

Aims:

• Aim 4: two scientific concepts (diffraction and interference) come together in this sub-topic, allowing students to analyse and synthesize a wider range of scientific information
• Aim 6: experiments could include (but are not limited to): observing the use of diffraction gratings in spectroscopes; analysis of thin soap films; sound wave and microwave interference pattern analysis
• Aim 9: the ray approach to the description of thin film interference is only an approximation. Students should recognize the limitations of such a visualization

Directly related questions

• 18M.2.HL.TZ2.5c: The slit separation is increased. Outline one change observed on the screen.
• 18M.2.HL.TZ2.5b: Monochromatic light from a single source is incident on two thin, parallel slits. The...
• 18M.2.HL.TZ2.5a: Monochromatic light from two identical lamps arrives on a screen.                              ...
• 18M.1.HL.TZ2.26: A beam of monochromatic light is incident on a diffraction grating of N lines per unit...
• 18M.2.HL.TZ1.3b.ii: Deduce, in mm, the width of one slit.
• 18M.2.HL.TZ1.3b.i: Calculate the angular separation between the central peak and the missing peak in the double-slit...
• 18M.1.HL.TZ1.28: Monochromatic light is incident on 4 rectangular, parallel slits. The first principal maximum is...
• 18M.1.HL.TZ1.27: Monochromatic light of wavelength λ in air is incident normally on a thin film of refractive...
• 17N.2.HL.TZ0.6b.i: State and explain the differences between the pattern on the screen due to the grating and the...
• 17N.2.HL.TZ0.6a.ii: The distance from the centre of the pattern to A is 4.1 x 10–2 m. The distance from the screen to...
• 17N.2.HL.TZ0.6a.i: Explain why zero intensity is observed at position A.
• 17N.1.HL.TZ0.29: A transparent liquid forms a parallel-sided thin film in air. The diagram shows a ray I incident...
• 17N.1.HL.TZ0.28: Monochromatic light is incident on two identical slits to produce an interference pattern on a...
• 17M.2.HL.TZ2.4c.ii: Suggest the variation in the output voltage from the light sensor that will be observed as the...
• 17M.2.HL.TZ2.4c.i: Determine the width of one of the slits.
• 17M.1.HL.TZ2.27: Blue light is incident on two narrow slits. Constructive interference takes place along the lines...
• 17M.1.HL.TZ1.27: For fringes to be observed in a double-slit interference experiment, the slits must emit waves...
• 16N.1.HL.TZ0.28: Light of wavelength λ is incident normally on a diffraction grating that has a slit separation...
• 16N.1.HL.TZ0.27: Monochromatic light is incident on a double slit. Both slits have a finite width. The light then...
• 16M.1.HL.TZ0.35: Which of the following...
• 16M.1.HL.TZ0.23: In a double-slit interference experiment, the following...
• 15M.3.HL.TZ1.13b: The following data are available: Refractive index of oil = 1.4Refractive index of water =...
• 15M.3.HL.TZ1.13a: Outline the process by which coloured fringes are formed.
• 15M.3.SL.TZ2.21a: Explain why an interference pattern is produced on the screen.
• 15M.3.SL.TZ2.21b: The two slits are separated by 2.2 mm and the distance from the slits to the screen is 1.8 m. The...
• 15N.3.HL.TZ0.11a: Calculate the wavelength of the light within the soap solution.
• 15N.3.HL.TZ0.11b: Calculate the minimum thickness of the soap film that results in constructive interference for...
• 15N.3.HL.TZ0.11c: Without a calculation, explain why a soap film that is twice as thick as that calculated in (b)...
• 14M.3.HL.TZ1.13a: Calculate the wavelength of the light.
• 14M.3.HL.TZ1.13b: The upper glass plate is now replaced with a curved glass plate. The dotted line represents the...
• 14N.1.HL.TZ0.16: Radiation is incident on a single rectangular slit. The diffracted beam that emerges from the...
• 14N.3.HL.TZ0.15b: When white light is normally incident on the surface of the oil, the film appears green to an...
• 14N.3.HL.TZ0.15a: Explain why the film of oil appears to show coloured fringes.
• 14M.3.HL.TZ2.14a: Determine the minimum thickness of the oil layer that gives rise to the least amount of light...
• 14M.3.HL.TZ2.14b: Describe the change in the intensity of the reflected light as the thickness of the oil layer in...
• 14M.3.SL.TZ2.19a: Outline what is meant by the term (i)     coherent. (ii)     monochromatic.
• 14M.3.SL.TZ2.19c: (i)     Show that the laser produces light of wavelength equal to 720 nm. (ii)     State the...
• 14M.3.SL.TZ2.19b: State the phase difference between the light waves from the two slits that meet at B.
• 13M.1.HL.TZ1.15: A parallel beam of monochromatic light of wavelength λ passes through a slit of width b and forms...
• 12M.1.HL.TZ2.18: A coherent beam of light of wavelength λ is incident on a double slit. The width of the slits is...
• 13M.3.SL.TZ1.21a: Laser light is monochromatic and coherent. Explain what is meant by (i) monochromatic. (ii)...
• 13M.3.SL.TZ1.12c: The number of lines per millimetre in the diffraction grating in (b) is reduced. Describe the...
• 13M.3.SL.TZ1.21b: A beam of laser light is incident normally on a diffraction grating which has 600 lines per...
• 13M.3.HL.TZ1.13a: State what phase change occurs on reflection at the air-coating boundary and at the coating-glass...
• 13M.3.HL.TZ1.13b: The thickness d of the coating layer is 110 nm. Determine the wavelength for which there is no...
• 13M.3.HL.TZ2.14a: A ray of monochromatic light is incident on a thin film of soap water that is suspended in air....
• 13M.3.HL.TZ2.14b: White light is incident normally on the soap film. The thickness d of the soap film is 225 nm and...
• 12N.3.SL.TZ0.20a: State the condition necessary to observe interference between two light sources.
• 11N.3.HL.TZ0.10b: State and explain how the fringe separation changes if the angle of the wedge is increased slightly.
• 11N.3.SL.TZ0.17b: The number of slits is now increased. State and explain the effect, if any, this has on the...
• 11N.3.HL.TZ0.10a: Outline how the fringes are formed.
• 12N.3.SL.TZ0.20b: The diagram below shows an arrangement for observing a double slit interference pattern. A...
• 12N.3.SL.TZ0.20c: The slits in (b) are replaced by a large number of slits of the same width and separation as the...
• 12M.3.SL.TZ2.19b: Suggest why, even though there are dark fringes in the pattern, no energy is lost.
• 12M.3.HL.TZ2.12a: Show that when θ=0 the condition for destructive interference between rays X and Y...
• 12M.3.HL.TZ2.12b: Light of wavelength 640 nm in air is incident normally on the glass surface. (i) Show that the...
• 13N.3.HL.TZ0.11a: An observer viewing the microscope slide at near-normal incidence measures the fringe spacing to...
• 11M.3.SL.TZ1.21a: Determine the angular separation of the two lines when viewed in the second order spectrum.
• 11M.3.SL.TZ1.21b: State why it is more difficult to observe the double yellow line when viewed in the first order...
• 11M.3.HL.TZ1.15a: Deduce that the thickness of the air wedge t that gives rise to a bright fringe, is given by...
• 11M.3.HL.TZ1.15b: The length of the air wedge, L, is 8.2 cm. The bright fringes are each separated by a distance of...
• 10N.3.HL.TZ0.G5a: State why the light reflected from the two microscope slides produces a system of interference...
• 10N.3.HL.TZ0.G5b: The condition that a bright fringe is observed in the field of view of the travelling microscope...
• 10N.3.HL.TZ0.G5c: In the diagram, the length of the slides is 5.00 cm. The wavelength of the monochromatic light is...
• 10N.3.SL.TZ0.G3b: For a particular grating, the distance between adjacent slits is...