Irina finds an unlabeled box of fine needles and wants to determine how thick they are. A standard ruler will not do the job, as each needle is less than a millimeter thick. So, to determine the thickness, she uses a needle to poke a hole in a piece of paper. Then, she positions a 670 nm laser pointer to shine through the hole and project a circular diffraction pattern on a wall 21.2 m away. She then uses her ruler to measure that the central bright circle is 19.7 cm in diameter. What diameter does Irina calculate for the needle?

Irina finds an unlabeled box of fine needles and wants to determine how thick they are. A standard ruler will not do the job, as each needle is less than a millimeter thick. So, to determine the thickness, she uses a needle to poke a hole in a piece of paper. Then, she positions a 670 nm laser pointer to shine through the hole and project a circular diffraction pattern on a wall 21.2 m away. She then uses her ruler to measure that the central bright circle is 19.7 cm in diameter. What diameter does Irina calculate for the needle?

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter27: Wave Optics

Section: Chapter Questions

Problem 69P

See similar textbooks

Similar questions

Irina finds an unlabeled box of fine needles, and wants to determine how thick they are. A standard ruler will not do the job, as each needle is less than a millimeter thick. So, to find the thickness, she uses a needle to poke a hole in a piece of brown construction paper. Then, she positions a 657 nm laser pointer to shine through the hole and project a circular diffraction pattern on a wall 22.7 m away. She then uses her ruler to measure that the central bright circle is 11.7 cm in diameter. What diameter does Irina calculate for the needle? diameter: um
Irina finds an unlabeled box of fine needles, and wants to determine how thick they are. A standard ruler will not do the job, as each needle is less than a millimeter thick. So, to find the thickness, she uses a needle to poke a hole in a piece of brown construction paper. Then, she positions a 670 nm laser pointer to shine through the hole and project a circular diffraction pattern on a wall 22.7 m away. She then uses her ruler to measure that the central bright circle is 15.2 cm in diameter. What diameter does Irina calculate for the needle?
Irina finds an unlabeled box of fine needles, and wants to determine how thick they are. A standard ruler will not do the job, as each needle is less than a millimeter thick. So, to find the thickness, she uses a needle to poke a hole in a piece of brown construction paper. Then, she positions a 640 nm laser pointer to shine through the hole and project a circular diffraction pattern on a wall 20.7 m away. She then uses her ruler to measure that the central bright circle is 19.2 cm in diameter. What diameter does Irina calculate for the needle? diameter: μm TOOLS x10
** 38. Two plastic plates (index of refraction n = 1.3) are separated by an air gap of 0.9 µm. Analyze the reflections of light of wavelength 600 nm and conclude whether it will be brightly reflected or not. 0.9 um gap ** 39. The air gap in the previous problem is now filled with a mineral oil whose index of refraction is n = 1.5. Analyze the reflections of light of wavelength 600 nm and conclude if it will be brightly reflected or not.
In the figure, first-order reflection from the reflection planes shown occurs when an x-ray beam of wavelength 0.820 nm makes an angle θ = 62.3˚ with the top face of the crystal. What is the unit cell size a0?
Diffraction can be used to provide a quick test of the size of red blood cells. Blood is smeared onto a slide, and a laser shines through the slide. The size of the cells is very consistent, so the multiple diffraction patterns overlap and produce an overall pattern that is similar to what a single cell would produce. Ideally, the diameter of a red blood cell should be between 7.5 and 8.0 μm. If a 633 nm laser shines through a slide and produces a pattern on a screen 24.0 cm distant, what range of sizes of the central maximum should be expected? Values outside this range might indicate a health concern and warrant further study.
The diameter of a thin wire is measured in a physics laboratory by a student. The wire is held vertically in a holding frame in front of the laser beam. The laser light diffracts on the wire and produces a diffraction pattern on a white screen. The diffraction pattern is shown in the figure. The pattern is centered around the origin. 4 3 2 1 y (cm) 0 -2 -3 -4 -8 -7 -6 -5 -4 -3 -2 -1 0 1 x (cm) 2 3 4 5 6 7 8 The wavelength of the laser light is 563 nm, and the screen is 1.37 m away from the wire. What is the diameter of the wire? (Hint: one of the higher order diffraction minima lines up with a well defined x-value. Also, it is perfectly safe to use the small angle approximation: sin() = tan(#)).
A microscope with an objective lens of diameter 7.70 mm is used to view samples of light of wavelength 650 nm.What is the limiting resolutions of this microscope with this objective lens.?
Problem 2. A) A Michelson interferometer uses light of wavelength 500 nm. The irradiance of the beam exiting the laser is IL. What are the possible differences in the lengths of the arms of the interferometer when the irradiance at the detector is IL/3? B) Young's Double slit experiment is performed with HeNe laser wavelength 632.8 nm. The screen is 2 m from the slits and the slit separation is 0.2 mm. Find the distance of the 3th bright fringe from the center of the interference pattern on the screen (call the central bright fringe the "Oth" fringe).
Babinet's principle says that the diffraction pattern observed when light falls on an aperture of any shape is the same as that obtained when light falls on an object that is the complement of such aperture. A laser with a wavelength of 600 nm is incident on a hair, generating a diffraction pattern with a width of the principal maximum of 10 mm on a screen located 1 m away from the hair. What is the diameter of this wire?
Consider a light wave passing through a slit and propagating toward a distant screen. Figure P37.53 shows the intensity variation for the pattern on the screen. Give a mathematical argument that more than 90% of the transmitted energy is in the central maximum of the diffraction pattern. Sugges- tion: You are not expected to calculate the precise percent- age, but explain the steps of your reasoning. You may use the identification 1 1 8 Imax asine -3T -27 -T 27 37 A Figure P37.53 ||
You stretch a strand of your hair across a laser beam and observe the diffraction pattern this produces on a sheet of paper 1.15 m from your hair strand. You mark the center of the dark regions on either side of the central bright spot and measure the distance between these marks to be 21.4 mm. You are given that the wavelength of the laser light is 633 nm. What is the diameter of your hair strand (in mm)? Make use of the small angle approximation. (Hint: recall Babinet's principle which equates the spot pattern created by light going around the hair to the pattern when light goes through a slit.)