Question

If a torch is used in place of monochromatic light in Young's experiment what will happens
A. Fringe will appear for a moment then it will disappear
B. Fringes will occur as from monochromatic light
C. Only bright fringes will appear
D. No fringes will appear

Answer 1

The double-slit experiment is a proof in contemporary physics that light and matter may exhibit properties of both conventionally defined waves and particles, as well as the essentially probabilistic nature of quantum mechanical processes. Thomas Young was the first to do this sort of experiment with light in 1801, as a demonstration of light's wave nature. Light was considered to be made up of either waves or particles at the time.

Complete answer:
A coherent light source, such as a laser beam, lights a plate punctured by two parallel slits, and the light travelling through the holes is viewed on a screen behind the plate in the simplest form of this experiment. Because light is a wave, it interferes with itself as it passes through the two slits, resulting in bright and dark bands on the screen, which would not be anticipated if light were made up of classical particles.

The light is always found to be absorbed at distinct places on the screen as individual particles (not waves), and the interference pattern develops when the density of these particle impacts on the screen varies. Furthermore, in variations of the experiment with detectors at the slits, each measured photon travels through one slit (as a classical particle would), rather than both (as would a wave).

However, similar tests show that particles do not produce the interference pattern when the slit through which they travel is detected. The idea of wave–particle duality is demonstrated by these findings. When we utilise a torch light instead of monochromatic light, the fringe pattern overlaps. As a result, no fringe will develop.Fringes are areas of contrasting brightness or blackness created by diffraction or interference of a measured wavelength of light in physics.

Hence option D is correct.

Note: Monochromatic light, often known as one-color light, is electromagnetic radiation produced from atom photon emissions. Photons move in the form of energy wave fronts of various lengths and energies. The frequency of light is determined by energy levels, and the duration of a wave defines its hue.