Question

In Young's double slit experiment, the interference pattern obtained with white light will be?

Answer 1

Hint: This question will begin with an explanation of Young's Double Slit Experiment, followed by a discussion of what would happen if we used white light instead of monochromatic light, and finally the required response.

Complete answer:
Thomas young performed an experiment in which he projected the light beams emerging from the slits onto another screen, using monochromatic light diffracted through the small slits as a source of coherent lighting. When the slits were large, placed far apart, and close to the screen, two overlapping patches of light formed on the screen, according to Young. The light traveling through the slits and onto the screen generated distinct bands of colour separated by black regions in a serial order when he reduced the size of the slits and moved them closer together. To characterize the bands, Young developed the term interference fringes and discovered that they could only be created if light behaved like a wave.

White light is made up of waves with a variety of wavelengths ranging from violet to red. When monochromatic light is replaced with white light in Young's interference experiment, the waves of each wavelength generate their own interference patterns. As a result, all of the other fringes have coloured edges, with the blue one being closer to the centre. The fringes eventually converge, resulting in a homogeneous white light.

Note:
When two light waves of the same frequency and phase difference move in the same direction and superpose, the intensity in the superposition zone is redistributed, becoming highest at some spots and minimum at others. Interference of light is the name given to this phenomena. Light sources that emit waves with a zero or constant phase difference and the same frequency are known as coherent sources.