# Optics

 Where is the image that appears in a plane mirror? Behind the mirror. It will also be upright T/F. Red and violet light travel at different speeds True. This is why when we say the index of refraction for glass is 1.5, it also means that the index varies for each photon. 1.47 for red, 1.54 for violet Violet light has the greatest angle of refraction Equation for critical angle sin Ocrit = n2/n1. n1 is index of medium that light is traveling through (incidence) Senlls law n1 sin O1 = n2 sin O2 Curved mirrors are also called? Spherical Distance b/w the center of curvature and the mirror is called the radius of curvature, r. So where is the focal lenght? Halfway between the center of curvature. f = 1/2 r Where is the image formed for concave and convex mirrors? CONCAVE Infront of the mirror and it will be inverted CONVEX Behind the mirror and upright Lens and mirror equation (1/o) + (1/i) = (1/f) o = object's distance from mirror (always positive)i = distance of image f = focal length magnification equation m - i/o if m is positive, the image is uprightif m is negative, the image is inverted T/F. Real images are upright, and virtual images are upright TRUE Mirror shortcut. fConcave +Convex - ii + = real imagei - = virtual image mm + = upright m - = inverted Usually i+ goes with m-; and i- goes with m+ Concave mirrors can create real and virtual images while convex mirros can only make virtual images. Image of plane mirror Virtual and upright. (real always always goes with inverted, and virtual always goes with upright. since the mirror makes an upright image, it is virtual) If an object is placed very far from a concave mirror, where will be the image form? At the focal point o = infinity so 1/o = 0, therfore 1/i = 1/f; i = f f is always 1/r and r is always 2f! Often the MCAT will give you the radius, so simply divide by 2. How do lenses form an image? Through refraction. Lenses are clear pieces of glass. Converging lenses Thicker around the middle.Refract light rays that are parallel toward the focal point on the other side of the lense Diverging lens Thinner in the middlerefract ligth that are parallel away from the axis of the focal point = infront of lens analagous to concave lens Lens shortcut Essentially same laws and rules except that converging lenses (convex) have a postive value for f while diverging lenses (converging) have a negative value for f. ii + = real imagei - = virtual image mm + = upright m - = inverted Usually i+ goes with m-; and i- goes with m+ Where are virtual images formed? Same side of the lens/mirror as the object; real and inverted on the other side Lens with a shorter focal lenght refracts more or less light? More, which also means that is has greater power Lens power P = 1/f; D in diopters; f in meters Define myopia and hyperopia myopia = nearsightedness (Cannot see far). Fix with digerging lens. hyperopia = farsigtedness (Cannot see near). Fix with converging lens. Authormightyred230 ID84422 Card SetOptics DescriptionMCAT Updated2011-05-09T05:14:50Z Show Answers