--%>

calculate the intensity I along y axis

As shown in the figure below, a source at S is sending out a spherical wave:

E1=(A×D/r) cos(wt-2πr/λ); where r is the distance to source S. In addition, there is another plane wave propagating along x axis: E2=Acos(wt-2πx/λ). 

These two waves both projected on a vertical screen as shown in the figure. Please calculate the intensity I along y axis (I should be a function of y, the distance from x axis). D is the distance between the screen and the source.

 

381_optics.png

Hint: For a wave E=E0cos (wt + q), I = 2 = E02. Also r = (D2 + y2)1/2.

For k<<1,  (1+k2)1/2» 1+k2/2.   cosA+cosB = 2cos[(A+B)/2] cos[(A-B)/2]

   Related Questions in Physics

  • Q : Explain Millikan oil drop experiment

    Millikan oil drop experiment (R.A. Millikan): A famed experiment designed to compute the electronic charge. The drops of oil were carried past a consistent electric field among charged plates. Subsequent to charging the drop with x-ra

  • Q : Explain Coulombs law Coulomb's law (C.

    Coulomb's law (C. de Coulomb): The basic law for electrostatics, equivalent to Newton's law of universal gravitation. It defines that the force between two point charges is proportional to the arithmetical product of their respective

  • Q : What are Woodward-Hoffmann rules

    Woodward-Hoffmann rules: The rules leading the formation of products throughout certain kinds of organic reactions.

  • Q : Define Systeme Internationale d'Unites

    Systeme Internationale d'Unites (SI): The rationalized and coherent system of units derived from the m.k.s. system (that itself is derived from metric system) in common utilization in physics nowadays.

  • Q : Explain Hawking radiation Hawking

    Hawking radiation (S.W. Hawking; 1973): The theory which black holes emit radiation similar to any other hot body. The virtual particle-antiparticle pairs are continuously being made in supposedly empty space. Infrequently, a pair wil

  • Q : Define Pascal or SI unit of pressure

    Pascal: Pa The derived SI unit of pressure stated as 1 N acting over a region of 1 m2; it therefore has units of N/m2

  • Q : Define Centrifugal pseudo force

    Centrifugal pseudo force: A pseudo force which takes place whenever one is moving in uniform circular motion. One feels a "force" directed outward from the center of the motion.

  • Q : How fireworks turn to shapes similar to

    Briefly illustrate how do fireworks turn to shapes similar to hearts and stars?

  • Q : Continuity of equation or Equation of

    Define Equation of continuity or Continuity of equation: An equation that states that a fluid flowing via a pipe flows at a rate that is inversely proportional to the cross-sectional region of the pipe. That is, when the pipe constric

  • Q : Define Kilogram or SI unit of mass

    Kilogram: kg: The basic SI unit of mass that is the only SI unit still maintained by a physical artifact: a platinum-iridium bar reserved in the International Bureau of Weights and Measures at Sevres, France.