Question

In case of Fraunhofer diffraction on a single slit the diffraction pattern on the screen correct for which of the following statements ?

• A. Central dark band having uniform brightness on either side.
• B. Central dark band having alternate dark and bright bands of decreasing intensity on either side.
• C. Central bride band having dark bands on either sides.
• D. Central bride band having alternate dark and bright bands of decreasing intensity on either side.

Answer 1

The Correct Option is D

When coherent light passes through a single slit, it creates a diffraction pattern on a screen. This pattern consists of alternating bright and dark bands. The central bright band is the brightest and widest, and its intensity diminishes moving outwards. This pattern is caused by constructive and destructive interference of diffracted light waves. Constructive interference creates the bright bands, while destructive interference creates the dark bands. Therefore, the described scenario is accurately depicted by option (D).

Answer 2

When a beam of light undergoes Fraunhofer diffraction after passing through a single slit, a distinctive pattern emerges on a screen positioned in the far field. This pattern is characterized by a prominent central bright band, also known as the central maximum. Flanking this central maximum on both sides are a series of alternating dark and bright bands. These are more formally referred to as secondary minima (dark bands) and secondary maxima (bright bands). A defining characteristic of this diffraction pattern is that the intensity of these secondary maxima progressively decreases as they are located further and further away from the intensely bright central maximum. The presence and arrangement of these alternating bands is a direct consequence of the wave nature of light and its interaction with the single slit, resulting in both constructive and destructive interference.