幼儿园课件故事小猪飞上天ppt课件-课件（PPT讲稿）.ppt

PH 113 MJM May 1,2008. Int/ Diffraction Wsheet Name________________________ Box___ 6 th____ 7 th___ ?r=w sin ?;I=I o cos 2( ?/2) I=I o [sin( ?/2) / ?/2] 2 double slit experiment is performed with light of wavelength 633 nm. The screen m horizontally from the slits. The slit separation mm. How many bright spots are there between the central bright spot and a point on the screen which mm vertically from the center? [ Hint: find the extra path.] IfI o is the intensity in the center of the pattern, find the intensity I at the point given above ( mm from the center) 2. Two narrow slits are illuminated by coherent light of wavelength 480 nm. This produces a pattern of alternating bright and dark bands ona screen several meters from the slits. The first bright spot away from the center is at an angle x10 -4 radians. If the maximum intensity isI oon the screen, calculate the intensity ? way between the bright spot in the center of the screen, and the closest dark spot. [ Hint: figure out how many wavelengths of extra path, then get ?] grating has a first-order maximum at20 o for light of wavelength 500 nm. What will the angle be for the bright spot in first order at600 nm? At500 nm, how many grating orders will be visible? How many total maxima are visible? 4. Coherent light of wavelength 500 nm is used to illuminate a single slit. On a screen m from the slit, the first small maximum of the diffraction pattern , mm from the bright central maximum. Which diagram would most accurately represents the situation at the maximum closest to the central bright spot i) straight line of arrows ii) half circle of arrows, iii) full circle of arrows iv) one and a half circles of arrows v) two full circles, vi) ?ofa circle of arrows slit of width mm m from a screen. When coherent light of wavelength 650 nm falls on this slit, a pattern of bright and dark light is formed on the screen. How far from the center (where it is