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Waves

1. Classification

   • Direction of motion of points
     • Longitudinal waves
       • *Vibration of the particle in the media being in the direction of wave propagation. *Compression,rarefaction
     • Transverse Waves
       • *Vibration of the particle in hte media being perrpendicular to the wave propogation *crests , troughs
   • Requirement of a medium
     • Mechanical wave
       • material medium necessary
     • Electromagnetic wave
       • material medium  not necessary
       • Radio Waves
         • AM--------LW,MW,SW FM
         • TV Waves
           • VHF UHF
           • Microwaves
             • Infrared
               • Visible
                 • Red Orange Yellow Green Blue Indigo Violet
                 • Ultraviolet
                   • X
                     • Gamma
   • Distance of energy propogation
     • Progressive wave
       • wave propagates to considerably larger distance
     • Standing wave
       • wave propagates to conssiderably shorter range
       • A stationary  wave results when two identical waves which are travelling in opposite directions are superposed.
       • All particles between two adjacent nodes are at the same phase .Wach particle in the next pair of adjacent nodes are out of phase by 180 degrees
       • Particles at the antinode move with  highest average speed

2. Wave Properties

   • Reflection
     • Laws of reflection
     • Reflection of pulses
   • Refraction
     • Refraction occurs duue to the change of speed i different medium llaws of refraction
   • Diffraction
     • Spreading of waves *narrow  aperture *long wavelength------------more  diffraction *small barrier            
   • Superposition
     • When two waves are superposed , their resultant is equal to the vector addition  of individual displacements
   • Interference
     • Constructive
     • Destructive
   • Beats
     • two notes with nearly equal frequencies. beat frequency=Difference of                                      frequencies
   • Polarization

3. Transverse Standing Waves in stretched strings

   • v=(T/m)½
   • f=(n+1)v/2L
   • f=(n+1)f0

4. Longitudinal Standing waves in pipes

   • Closed pipes
     • f=(2n+1)v/4(L+e)
     • f=(2n+1)f0
   • v=(£RT/M)½
   • Open pipes
     • f=(n+1)v/2(L+2e)
     • f=(n+1)f0

5. Longitudinal waves in a rod

   • One end clamped
     • f=(2n+1)v/4L
     • f=(2n+1)f0
   • V=(Y/P)½
   • Middle clamped
     • f=(2n+1)v/2L
     • f=(2n+1)f0