Quiz Introduction OBJECTIVES The transmission of light across a boundary between two media is accompanied by a change in both the speed and wavelength of the wave. This can result in a change of direction at the boundary, a phenomenon known as refraction. In this experiment you measure the change in direction of light beams as they refract or reflect at a boundary to determine the index of refraction of a transparent object. The objectives of this experiment are as follows: 1. To measure the angles of incidence and refraction at a boundary between media 2. To observe total internal reflection at a boundary between media 3. To calculate the critical angle of a boundary between media Theory Part 1 WHAT IS REFRACTION? Refraction is the bending of light. This occurs when light travels through one material to another (ex: air, water, etc…) For example, when looking at a glass of water with a straw in it, the straw may appear to be broken. This happens because light moves more slowly in water than in air. As a result, the light bends as it passes from air to water, making the straw appear to be bent. Mathematically, Snell's law describes the relationship between the angle of incidence of a beam of light as it intersects a new transparent medium and the angle of refraction as enters that transparent medium. Snell's law quantifies the relationship that is observed in above: n1∙ sin θ1 = n2∙ sin θ2 where n1 is the index of refraction of medium 1, n2 is the index of refraction medium 2, θ1 is the angle that the light ray makes with respect to the normal in medium 1, θ2 is the angle that the light ray makes with respect to the normal in medium 2. Theory Part 2 When the angle of incidence from denser medium to a lighter medium reaches a certain critical value, the refracted ray lies along the boundary, having an angle of refraction of 90-degrees. This angle of incidence is known as the critical angle; It is the largest angle of incidence for which refraction can still occur. For any angle of incidence greater than the critical angle, light will undergo total internal reflection. Note that this only happens for light traveling from a denser medium to a lighter one The equation for the critical angle is: Where, θc n2 n1 Question 1 (1 point) Saved The critical angle. Refraction index. Incident index. What is Refraction? Question 1 options: The reflection of light. The color change of light. The bending of light. The frequency change of light. Question 2 (1 point) Saved What is the critical angle? Question 2 options: The angle of incidence for which the angle of refraction is 45°. The angle for which light stop travelling. The angle of refraction for which the angle of incidence is 90°. The angle of incidence for which the angle of refraction is 90°. Question 3 (1 point) Saved What is the accepted value for the index of refraction in air? Question 3 options: n = 1.33 n = 0.75 n = 1.00 n = 0.00 Question 4 (1 point) Saved When light moves from a low index of refraction to a higher index of refraction, light will bend: Question 4 options: Away from the normal. Not enough information is provided to answer this question. Have no change. Towards the normal. Question 5 (1 point) Saved When light enters at an angle of 90° to the surface (boundary between the mediums), the angle of reflection will be? Question 5 options: 0° Not enough information is provided to answer this question. Towards the normal. Away from the normal. Question 6 (1 point) Saved 100% of the intensity of light will always be transmitted from medium 1 into medium 2? Question 6 options: True False Question 7 (1 point) Saved The bending of light as it moves from one medium to another with differing indices of refraction is due to a change in what property of the light? Question 7 options: amplitude frequency speed color Question 8 (1 point) Saved A beam of light passes from air into water. Which of the following statements is true? Question 8 options: a) Both the wavelength and frequency decrease. b) The frequency is unchanged and the wavelength increases. c) Both the wavelength and frequency increase. d) The frequency is unchanged and the wavelength decreases. e) The wavelength is unchanged and the frequency decreases. Question 9 (1 point) Saved A scuba diver shines a flashlight from beneath the surface of water (n = 1.33) such that the light strikes the water-air boundary with an angle of incidence of 43°. At what angle is the beam refracted? Question 9 options: a) 31° b) 43° c) 90° d) 48° e) 65° Question 10 (1 point) Saved A ray of light propagates in water (n = 1.333) and strikes a sheet of crown glass (n = 1.523). If the angle of refraction in the glass is 35.2°, determine the angle of incidence. Question 10 options: a) 41.2° b) 35.2° c) 30.3° d) 32.8° e) 45.0° Question 11 (1 point) Saved Which one of the following expressions determines the critical angle for quartz (n = 1.5) immersed in oil (n = 1.1)? Question 11 options: a) sin (1.1/1.5) b) tan-1 (1.1/1.5) c) 1.1/1.5 d) sin-1 (1.1/1.5) e) sin-1 (1.5/1.1) Question 12 (1 point) Saved A ray of light originates in medium A and is incident upon medium B. For which one of the following pairs of indices of refraction for A and B is total internal reflection not possible? Question 12 options: a) nA = 1.12 nB = 1.06 b) nA = 2.54 nB = 1.63 c) nA = 1.26 nB = 1.15 d) nA = 1.36 nB = 1.00 e) nA = 1.28 nB = 1.36 Submit Quiz12 of 12 questions saved