| The Following Topics Might Appear on Exam 3 (2020) |
| Poynting vector and the direction of EM wave propagation |
| Orientation of E and B Fields in an EM wave |
| Intensity as a function of Emax |
| Index of Refraction: n = c/v |
| Wavelength, speed, frequency of light in a medium with index of refraction n |
| Snell's Law |
| Frequency of wave is unchanged as it crosses an interface, even though speed and wavelength are not |
| Total internal reflection & critical angle |
| Dispersion: index of refraction depends on wavelength (explains rainbow) |
| When an unpolarized beam of intensity I0 passes through a polarization filter, the intensity of the resulting polarized beam is I0/2 |
| Polarization: Malus' Law |
| Brewster's angle |
| Two ways to polarize: filter & reflection |
| Huygen's principle: Every point on a wave front is itself a source of a wave front |
| Definition of image magnification: (image height)/(object height) |
| Definition of virtual image (light appears to diverge from its points, but it doesn't actually) |
| Definition of real image (light actually diverges from its points) |
| Mirror Equation |
| Defintions of focal point and focal length |
| Focal length of spherical mirror of radius R |
| Virtual image position due flat refracting surface (swimming pool) |
| Graphical methods for mirrors |
| Graphical methods for lens |
| Thin lens equation |
| Lens maker's equation |
| Diverging (f<0) lens vs Converging lens (f>0) |
| Definition of diopter |
| Lens to correct for nearsightedness |
| Lens to correct for farsightedness |
| Helpful Rules of Thumb (that follow from equations mentioned above): q < 0 for virtual image q > 0 for real image Virtual images are not inverted Real images are inverted Only convergent lenses or convergent mirrors can form real images The radius of curvature R for a flat surface is infinite The magnification due to a flat surface is always +1 The stronger a lens, the higher its diopter The virtual images of converging mirrors have a positive magnification M > 1 (upright image bigger than object) The virtual images of diverging mirrors have a positive magnification M < 1 (upright image smaller than object)) A converging mirror produces a virtual image if p < f, no image if p = f, and a real image if p > f A converging lens produces a virtual image if p < f, no image if p = f, and a real image if p > f A convex lens is converging, but a convex mirror is diverging. A concave lens is diverging, but a concave mirror is converging. |
| Path length differences resulting in constructive and destructive interference Constructive: Δr = mλ Destructive: Δr = (m + ½)λ, m = 0, ±1, ±2, ±3,... |
| Positions of bright and dark bands in two-slit interference ybright = Lmλ/d, ydark = L(m + ½)λ/d, m = 0, ±1, ±2, ±3,... |
| Angles of bright and dark bands in two-slit interference: sin(θBright) = nλ/d sin(θDark) = (n + 1/2)λ/d n = 0, ±1, ..., d = slit separation |
| Angles of dark bands due to single-slit diffraction: sin(θDark) = nλ/d, n = ±1, ±2, ..., d = slit width, |
| Angles of bright bands due to diffraction grating: sin(θBright) = nλ/d, n = 0, ±1, ..., d = separation between grating |
| Bragg's Law |
| The double slit experiment: produces an interference pattern even when particles of light emerge from their source one at a time. |
| Exam will: |
| be closed book, closed notes. |
| be 25 questions |
| be 1 hour 15 minutes long |
| be entirely multiple choice |
| allow calculators |
| provide value of constants you might need |