incidence for total internal reflection. Figure 2. Refraction (and reflection) at the interface of two different media. The reflected ray obeys the Law of Reflection, and the refracted ray obeys Snell’s Law. Lenses By applying the laws of reflection and refraction to mirrors and lenses, respectively, one arrives at the following expression: (2) where p is the distance from the mirror/lens (object distance) and q is the distance to the object from the mirror/lens (image distance); f means the focal length of the mirror/lens to the image in use. The focal length is defined as the point at which all parallel rays of light meet after reflecting off of the mirror or passing through the lens. For diverging mirrors/lenses, it is the point from which the diverging rays appear to come. This is shown for lenses in Figure 3.When multiple lenses are used, one treats one lens at a time. Equation 2 is applied to the first lens using its focal length to find the image distance given a known object distance This image then f1 q1, p1. becomes the object for the second lens, where one needs to figure out the object distance and p2 then use it with the focal length of lens #2 (f2) to find the final image distance This process q2. repeats for as many lenses as are in the array. Figure 3. Parallel rays incident on a convex (converging) lens (top) and onto a concave (diverging) lens (bottom). The focal lengths are labelled f. Procedure Lenses Using the optical bench allow light from a distant light source (p to fall on a → ∞) converging lens. Move the lens until a clear image is formed on the screen. The screen should be on the opposite side of the lens from the light source. Record the distance from the lens to the screen Repeat this for the two other converging lenses, and record the q. – focal lengths for later use. Using a small light source (arrows), move the lens until the image of the light source is clearly focused on the screen. Record the distance from the light source to the lens (p) and the distance from the lens to the screen (q). Repeat this for three different object distances. Repeat the above step for the other two lenses from the first part.
incidence for total internal reflection. Figure 2. Refraction (and reflection) at the interface of two different media. The reflected ray obeys the Law of Reflection, and the refracted ray obeys Snell’s Law. Lenses By applying the laws of reflection and refraction to mirrors and lenses, respectively, one arrives at the following expression: (2) where p is the distance from the mirror/lens to the object (object distance) and q is the distance from the mirror/lens to the image (image distance); f means the focal length of the mirror/lens in use. The focal length is defined as the point at which all parallel rays of light meet after reflecting off of the mirror or passing through the lens. For diverging mirrors/lenses, it is the point from which the diverging rays appear to come. This is shown for lenses in Figure 3.When multiple lenses are used, one treats one lens at a time. Equation 2 is applied to the first lens using its focal length f1 to find the image distance q1, given a known object distance p1. This image then becomes the object for the second lens, where one needs to figure out the object distance p2 and then use it with the focal length of lens #2 (f2) to find the final image distance q2. This process repeats for as many lenses as are in the array. Figure 3. Parallel rays incident on a convex (converging) lens (top) and onto a concave (diverging) lens (bottom). The focal lengths are labelled f. Procedure Lenses Using the optical bench allow light from a distant light source (p → ∞) to fall on a converging lens. Move the lens until a clear image is formed on the screen. The screen should be on the opposite side of the lens from the light source. Record the distance from the lens to the screen – q. Repeat this for the two other converging lenses, and record the focal lengths for later use. Using a small light source (arrows), move the lens until the image of the light source is clearly focused on the screen. Record the distance from the light source to the lens (p) and the distance from the lens to the screen (q). Repeat this for three different object distances. Repeat the above step for the other two lenses from the first part.
ReflectionAndRefraction.docx