Microwaves of wavelength 10.0 mm fall normally on a metal plate that contains a slit 25 mm wide. (a) Where are the first minima of the diffraction pattern? (b) Would there be minima if the wavelength were 30.0 mm?
Week 4 Tuesday, September 13, 2016 10:45 AM E field of nonconducting infinite plane sheet of charge: Pos charge per unit area Symm analysis: Made up of infinite number of point charges Field must be perpendicular to sheet Field is directed towards or away from sheet For cylindrical gaussian surface: Flux thru ends is EA , no field thru curved part of surface Field is away from sheet Find field above/belowsheet with uniform negative charge per unit area (cylindrical) Same as above: sum top bottom and side. But E will be negative in bottom equation bc field is pointing towards sheet Parallel Plate Capacitor- plates of neg and pos charge w same charge density For pos plate, E field points away from plate at all positions For neg plate, E field points towards plate at all positions Total E field is sum of E+ and E- at all positions Ex) nonuniform Wab=Fconservativex d= -(Peb-Pea)= - PE Wab=Fconservativex d= -(Peb-Pea)= - PE Work done by conserv force= -change of PE Conserv force PE Where PE: electric PE diff(final-intial) Electric PE- scalar Change od electric PE is independent of path, depends on distance PE(path1)= PE(path2) To obtain electric PE diff: