Question

A beam of orange light illuminates two slits that are closely spaced. The resulting intensity pattern is a series of bright and dark fringes. What happens to the intensity pattern if we now change to blue light?

1) Nothing changes.
2) The series of bright and dark fringes changes to circular fringes.
3) The series of bright and dark fringes spreads out.
4) The series of bright and dark fringes gets closer together.
5) The series of bright and dark fringes disappears.

Answer 1

Changing orange light to blue light in a double-slit experiment results in interference fringes that are closer together due to blue light's shorter wavelength.

Step-by-step explanation:

When a beam of orange light illuminates two slits in a double-slit experiment, the resulting pattern consists of a series of bright and dark fringes, known as interference fringes. If we change the light to blue, which has a shorter wavelength than orange light, the spacing of the fringes is affected.

According to the equation d sin θ = mλ, where d is the slit separation, θ is the angle, m is the fringe order, and λ is the wavelength, we understand that the fringe spacing is proportional to the wavelength. Blue light, having a shorter wavelength, will produce fringes that are closer together compared to the fringes produced by orange light.