--%>

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 : Problem on beam For the beam

    For the beam illustrated below, we require to determine: (A) the support reactions

  • Q : Explain Planck radiation law Planck

    Planck radiation law: The law which explained blackbody radiation better than its precursor, therefore resolving the ultraviolet catastrophe. This is based on the supposition that electromagnetic radiation is quantized.

    Q : Define Constancy principle Constancy

    Constancy principle (A. Einstein): One of the postulates of Sir Einstein's special theory of relativity that puts forth that the speed of light in vacuum is computed as similar speed to all observers, in spite of of their relative mot

  • Q : Define Spin-orbit effect Spin-orbit

    Spin-orbit effect: The effect that causes atomic energy levels to be split since electrons contain intrinsic angular momentum (that is spin) in summation to their extrinsic orbital angular momentum.

  • Q : Define Tardon Tardon : A particle that

    Tardon: A particle that has a positive real mass and travels at a speed very less than c in all inertial frames.

  • Q : State Kohlrauschs law Kohlrausch's law

    Kohlrausch's law (F. Kohlrausch): When a salt is dissolved in water, the conductivity of the solution is the addition of two values -- one depending on the positive ions and the other on negative ions.

  • Q : Define Occams razor or Ockhams razor

    Occam's [or Ockham's] razor (William of Occam [or Ockham]; c. 1340): It is the suggestion that the simpler a theory is the better. When two theories forecast the phenomena to the similar accuracy, then the one that is simpler is the better one. Furthe

  • Q : What do you mean by the term density

    What do you mean by the term density? Briefly explain it.

  • Q : Explain Schroedingers cat

    Schroedinger's cat (E. Schroedinger; 1935): A thought experiment designed to exemplify the counterintuitive and strange ideas of reality that come all along with the quantum mechanics. A cat is sealed within a clos

  • Q : What is Hawking temperature Hawking

    Hawking temperature: The temperature of a black hole is caused by the emission of the hawking radiation. For a black hole with mass m, it is illustrated as: T = (hbar c3)/(8 pi G k m).