Electromagnetic Waves Multiple Choice Practice Problems Slide 3 / - PDF document

Slide 1 / 51 Slide 2 / 51 Electromagnetic Waves Multiple Choice Practice Problems Slide 3 / 51 Slide 4 / 51 1 Which of the following theories can explain the 2 The wave theory of light is associated with: bending of waves behind obstacles into “shadow region”? A Isaac Newton B Albert Einstein A Particle theory of light C Max Plank B Wave theory of light D Christian Huygens C Kinetic theory E Robert Milliken D Special theory of relativity E Classical mechanics Slide 5 / 51 Slide 6 / 51 3 A beam of light has a wavelength of 600 nm in air. 4 A light beam changes its direction when it strikes What is the frequency of light? (c = 3x10 8 m/s) a boundary between air and water. Which of the following is responsible for this phenomenon? 5.0x10 14 Hz A A Diffraction 2.0x10 14 Hz B B Interference 3.0x10 14 Hz C C Reflection 6.0x10 14 Hz D D Refraction 2.0x10 14 Hz E E Polarization

Slide 7 / 51 Slide 8 / 51 5 A light beam traveling in air with a wavelength of 6 A light beam traveling in air with a wavelength of 600 nm falls on a glass block. What is the speed 600 nm falls on a glass block. What is the of the light beam in glass? (c = 3x10 8 m/s, n = 1.5) wavelength of the light beam in glass? (n = 1.5) 3.0x10 8 m/s A 500 nm A B 400 nm B 2.0x10 8 m/s 1.5x10 8 m/s C 600 nm C 1.0x10 8 m/s D 300 nm D 0.5x10 8 m/s E 900 nm E Slide 9 / 51 Slide 10 / 51 7 A light beam traveling in air with a wavelength of 8 Which of the following is the correct order of 600 nm falls on a glass block. What is the electro-magnetic radiation with an increasing frequency of the light beam in glass? (c = 3x10 8 frequency? m/s, n = 1.5) A Radio Waves, Visible Light, IR Radiation, UV 5.0x10 14 Hz A Radiation, X-Rays, γ –Rays 2.5x10 14 Hz B B γ –Rays, Visible Light, IR Radiation, UV Radiation, X-Rays, Radio Waves 3.0x10 14 Hz C C Radio Waves, UV Radiation, Visible Light, IR 6.0x10 14 Hz D Radiation, X-Rays, γ –Rays 2.0x10 14 Hz E D Radio Waves, Visible Light, X-Rays, IR Radiation, UV Radiation, γ –Rays E Radio Waves, IR Radiation, Visible Light, UV Radiation, X-Rays, γ –Rays Slide 11 / 51 Slide 12 / 51 9 A light beam spreads when it travels through a 10 In Young’s double-slit experiment a series of narrow slit. Which of the following can explain this bright and dark lines was observed. Which of the phenomenon? following principles is responsible for this phenomenon? A Polarization A Polarization B Reflection B Reflection C Dispersion C Dispersion D Diffraction D Interference E Refraction E Refraction

Slide 13 / 51 Slide 14 / 51 11 Which of the following electro-magnetic waves 12 A blue beam of light falls on two narrow slits can be diffracted by a building? producing an interference pattern on a screen. If instead blue light a red beam of light was used in the same experiment, which new changes to the A Radio waves interference pattern we can observe? B Infrared waves C Ultraviolet waves A Interference fringes move close to the central maximum D Visible light B Interference fringes move away from the central E γ-Waves maximum C No change in interference D Bright fringes are replaced with dark fringes E The number of fringes increases Slide 15 / 51 Slide 16 / 51 13 In a Young’s double-slit experiment interference 14 Two coherent light waves approaching a certain pattern is observed on a screen. The apparatus is point on a screen produce a constructive then submerged into water. What is the new interference. The optical extra distance traveled change in the interference pattern? by one of the waves is: A Interference fringes move close to the central A λ/2 maximum B λ/3 B Interference fringes move away from the central C 3λ/2 maximum D λ C No change in interference E 5λ/2 D Bright fringes are replaced with dark fringes E The number of fringes increases Slide 17 / 51 Slide 18 / 51 15 In a Young’s double-slit experiment the distance 16 In a double-slit experiment a distance between the between the slits increases. What happens to the slits is doubled. What happens to the separation separation between the fringes? between the two adjacent maxima? A Increases A Doubles B Decreases B Quadruples C Stays the same C Is cut to a half D Increases for the bright fringes and decreases D Is cut to a quarter for the dark fringes E Stays the same E Increases for the dark fringes and decreases for the bright fringes

Slide 19 / 51 Slide 20 / 51 17 In a single-slit experiment as a result of 18 A light beam falls on a thin film and partially interference of a laser beam a student observes a reflects from the film and partially transmits set of red and dark concentric circles. When he through the film. What is the phase difference increases the slit separation what happens to the between the reflected and transmitted waves? interference pattern? A λ A The separation between the circles increases B 2λ B The separation between the circles decreases C λ/3 C No change in interference pattern D λ/4 D The separation between the circles increases E λ/2 and then decreases E The separation between the circles decreases and then increases Slide 21 / 51 Slide 22 / 51 19 A light beam traveling in water enters air. What is 20 A light beam of coherent waves with a wavelength the phase difference between the incident and of 600 nm falls perpendicularly on a diffraction transmitted waves? grating. The separation between two adjacent slits is 1.8 µm. What is the maximum number of spectral orders can be observed on a screen? A 0 B 2λ A 1 C λ/3 B 2 D λ/4 C 3 E λ/2 D 4 E 5 Slide 23 / 51 Slide 24 / 51 21 Sun rays fall on a glass prism. Which of the 22 Unpolarized light passes through two Polaroids; following rays will be refracted the least? the axis of one is vertical and that of the other is 60 ̊ to the vertical. If the intensity of the incident light is I 0 , what is the intensity of the transmitted light? A Blue B Violet C Green A I 0 D Yellow B I 0 /4 E Red C I 0 /3 D I 0 /2 E I 0 /8

Slide 25 / 51 Slide 26 / 51 1. Coherent monochromatic light falls normally on two slits separated by a distance d = 2.2 mm. The interference pattern is observed on a screen L = 4 m from the slits. a. What is the result of the interference at point A? b. What is the wavelength of the incident light? Free Response c. Determine the angular width between two second order maxima. d. If one of the slits is covered with a glass block and two waves emerge from the slits 180 ̊ out of phase. Describe the interference pattern on the screen. Slide 27 / 51 Slide 28 / 51 1. Coherent monochromatic light 1. Coherent monochromatic light falls normally on two slits separated falls normally on two slits separated by a distance d = 2.2 mm. The by a distance d = 2.2 mm. The interference pattern is observed on a interference pattern is observed on a screen L = 4 m from the slits. screen L = 4 m from the slits. a. What is the result of the interference b. What is the wavelength of the incident at point A? light? Slide 29 / 51 Slide 30 / 51 1. Coherent monochromatic light 1. Coherent monochromatic light falls normally on two slits separated falls normally on two slits separated by a distance d = 2.2 mm. The by a distance d = 2.2 mm. The interference pattern is observed on a interference pattern is observed on a screen L = 4 m from the slits. screen L = 4 m from the slits. c. Determine the angular width between d. If one of the slits is covered with a two second order maxima. glass block and two waves emerge from the slits 180 ̊ out of phase. Describe the interference pattern on the screen.