Question

In a double-slit experiment, light with a wavelength λ passes through a double-slit and forms an interference pattern on the screen at a distance L from the slits. What statement is true for the resulting interference pattern if the frequency of the light increases?

The distance between maxima increases.

Not enough information given.

The distance between maxima stays the same.

The distance between maxima decreases.

Answer 1

The distance between maxima will decrease.

Reason: When frequency of incident light is increased, wavelength decreases which results in decrease in fringe width of the pattern; fringe width is the distance between two consecutive bright fringes or two consecutive dark fringes.

So, when fringe width decreases, the maxima of the pattern comes closer or we can say that distance between maxima decreases.

=>fringe width=(wavelength *distance between slit and screen) / distance between slits