Two slits separated by a distance of d = 0.12 mm are located at a distance of D = 0.63 m from a screen. The screen is oriented parallel to the plane of the slits. The slits are illuminated by a coherent light source with a wavelength of λ = 540 nm. A wave from each slit propagates to the screen. The interference pattern shows a peak at the center of the screen (m=0) and then alternating minima and maxima. What is the pathlength difference between the waves at the second maximum (m=2) on the screen?

The path-length difference is

The angle is  

Explanation:

  From the question we are told that

             The distance of separation is  d = 0.12 mm =

             The distance from the screen is  D = 0.63 m

              The wavelength is

From the question we can deduce that the the two  maxima's are at the m=0 and m=2

   Now the path difference for this second maxima is mathematically represented as

  Where d is the path length difference

Substituting values

converting to mm

To obtain the angle we make the subject

 Substituting values

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