Reading Assignment Diffraction

11/16/23, 6:33 PM Reading Assignment 11: Diffraction: Attempt review Started on Saturday, 28 November 2020, 12:34 PM State Finished Completed on Saturday, 28 November 2020, 1:24 PM Time taken 49 mins 59 secs Marks 4.50/6.00 Grade 75.00 out of 100.00 Question 1 Correct Mark 1.00 out of 1.00 Which physicist used diffraction to demonstrate that light was a wave and had an experiment which he probably never performed himself named after him? Select one: Thomas Young Cross out «” James Clerk Maxwell cross out Christiaan Huyghens cross out Sir Isaac Newton cross out Albert Michelson cross out Your answer is correct. Thomas Young was the first person to show light was a wave using diffraction but he used a thin piece of card and not two narrow slits. The correct answer is: Thomas Young Marks for this submission: 1.00/1.00. https://eclass.srv.ualberta.ca/mod/quiz/review.php?attempt=6614762&cmid=4375437 1/6

11/16/23, 6:33 PM Reading Assignment 11: Diffraction: Attempt review Question 2 Correct Mark 1.00 out of 1.00 If you are standing outdoors near the corner of a building, you can hear sound waves from a person who is around the corner and out of sight when there are no other obstacles nearby. This is mainly because of of sound waves. Select one: refraction cross out diffraction Cross out ¢ interference cross out dispersion cross out reflection cross out Your answer is correct. Waves interact with edges and boundaries, which allows the waves to diffract around corners. The correct answer is: diffraction Marks for this submission: 1.00/1.00. Question 3 Correct Mark 0.50 out of 1.00 Which one of the following is NOT an assumption we make when deriving the single and double slit diffraction patterns? Select all that apply: the slits are uniformly illuminated cross out the light source illuminating the slits is coherent cross out the screen is placed a long way from the slits cross out light behaves as a wave cross out the width of the slit (for single slits) or the separation of the slits €ross out « (for double slits) is less than one wavelength of light Your answer is correct. The correct answer is: the width of the slit (for single slits) or the separation of the slits (for double slits) is less than one wavelength of light Marks for this submission: 1.00/1.00. Accounting for previous tries, this gives 0.50/1.00. https://eclass.srv.ualberta.ca/mod/quiz/review.php?attempt=6614762&cmid=4375437 2/6

11/16/23, 6:33 PM Reading Assignment 11: Diffraction: Attempt review Question 5 Correct Mark 0.00 out of 1.00 When we consider two slit interference, what assumption allows us to ignore the effects of single slit diffraction? We assume that... Select one: the slit separation distance is much smaller than the wavelength the width of each slit is much smaller than the wavelength the width of each slit is much larger than the wavelength the slit separation distance is much smaller than the distance to the screen the light is monochromatic Your answer is correct. Ccross out Cross out cross out cross out Ccross out First consider a single slit: when the slit width is much smaller than the wavelength, the central bright fringe expands to fill the screen with nearly-uniform light, so the usual single-slit diffraction pattern is not seen. When light passes through a two such slits, only the effect of double slit interference is seen. We can call this a perfect (or ideal) double slit pattern. The correct answer is: the width of each slit is much smaller than the wavelength Marks for this submission: 1.00/1.00. Accounting for previous tries, this gives 0.00/1.00. https://eclass.srv.ualberta.ca/mod/quiz/review.php?attempt=6614762&cmid=4375437 4/6

11/16/23, 6:33 PM Reading Assignment 11: Diffraction: Attempt review Question 6 Correct Mark 1.00 out of 1.00 Consider the difference between a double, narrow slit interference pattern, and the diffraction pattern produced when light shines through a single, wide slit. Which statements(s) is/are correct? Caution: There may or may not be more than one correct answer. Select all correct answers and no wrong answers for full credit. Select all that apply: Double-slit and single-slit patterns are identical cross out In a single slit pattern, bright fringes near the centre of the pattern cross out have equal widths In a double, narrow slit pattern, bright fringes near the centre of Cross out the pattern have equal widths In a single, wide slit pattern, the central bright fringe is wider cross out ¢ and brighter than any of the side fringes In a double, narrow slit pattern, the central bright fringe is wider cross out and brighter than any of the side fringes When there is only one slit, a single shaft of light strikes the centre cross out of the screen, and there are no side fringes Your answer is correct. In a double-slit pattern, if the slit-width is much smaller than the wavelength, the result is a double, narrow slit interference pattern. Bright fringes near the centre of the pattern are equally wide and equally bright. In a single slit diffraction pattern, the most of the light energy is in the central bright fringe, which is wider and brighter than any of the side fringes. The correct answers are: In a double, narrow slit pattern, bright fringes near the centre of the pattern have equal widths, In a single, wide slit pattern, the central bright fringe is wider and brighter than any of the side fringes Marks for this submission: 1.00/1.00. https://eclass.srv.ualberta.ca/mod/quiz/review.php?attempt=6614762&cmid=4375437 5/6