--%>

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 Tachyon paradox Tachyon

    Tachyon paradox: The argument explaining that tachyons (should they subsist, of course) can’t carry an electric charge. For an imaginary-massed particle travelling faster than c, less energy the tachyon has, the faster it travels, till at zero e

  • Q : What is Geometrized units Geometrized

    Geometrized units: The system of units whereby certain basic constants (G, c, k, and h) are set to unison. This makes computations in certain theories, like general relativity, much simpler to deal with, as such constants appear often.

    Q : Define Henry or SI unit of inductance

    Henry: H (after W. Henry, 1775-1836): The derived SI unit of inductance, stated as the inductance of a closed circuit in which the electromotive force of 1 V is generated whenever the electric current differs uniformly at a rate of 1

  • Q : Motion balance principle Explain in

    Explain in detail the motion balance principle

  • Q : Explain Keplers laws or Keplers

    Explain Keplers laws or Keplers first law, second law and third law? Kepler's laws (J. Kepler) Kepler's first

  • 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 Zeeman Effect or Zeeman line

    Zeeman Effect: Zeeman line splitting (P. Zeeman; 1896): Zeeman Effect is the splitting of lines in a spectrum whenever the source is exposed to the magnetic field.

  • Q : Explain Photoelectric effect

    Photoelectric effect: An effect described by A. Einstein that demonstrates that light seems to be made up of particles, or photons. The light can excite electrons (termed as photoelectrons in this context) to be ejected from the metal. Light with a fr

  • Q : Weights in pounds of the liquid gallons

    Write down the weights in pounds of the liquid gallons? Briefly describe it.

  • Q : Calculate power consumed : A voltage v

    : A voltage v = 150 + j180 is applied across an impedance and the current flowing is I = 5 - j4 find ? A, impedance . B, resistance. C, reactance. D, power consumed.