Thin film interference in a soap film The image of a soap fi

Thin film interference in a soap film The image of a soap film, shown above, has been decomposed into its three colors: red, green and blue. These images, shown below, are in black and white to hide their true color. Determine, based on the fringe pattern, which color belongs with each image.

Solution

Ans:First thing regarding the interference fringe pattern is that the width of a bright or dark fringes is proportional to its wavelength.So the width of bright fringes for blue light will be smaller than the green or red light.

Then if we take a particular postion in the screen or on the bubble soap, there the number of blue fringes will be greater, the number of green fringes will be medium and the number of red fringes will be less.

Here on the lower ist image the no of bright fringes is 8 , in the middle one the no. of bright fringes is 7 and in the last right image the no of bright fringes is 6.

So the 1st one is blue the 2nd one is green and the third one is red.

And the wave length of blue is smaller(450nm) , green medium(495 nm) and the red has longer(620 nm).