In Thomas Young’s double split experiment if the source is moved closer to any one of the slit then what would be the central maximum .

In Thomas Young's double-slit experiment, the arrangement of light passing through two closely spaced slits creates an interference pattern on a screen. This pattern consists of alternating bright and dark fringes, with the central maximum being the brightest point directly in line with the light source and the midpoint between the two slits. If the light source is moved closer to one of the slits, it will affect the interference pattern, particularly the position and intensity of the central maximum.

Impact of Moving the Light Source

When the light source is shifted closer to one of the slits, several changes occur in the interference pattern:

• Intensity Variation: The brightness of the central maximum may increase because the light intensity from the nearer slit becomes more pronounced. This is due to the fact that light intensity diminishes with distance, so the slit closer to the source will emit more light compared to the other slit.
• Path Length Difference: The path length difference between the light waves emanating from the two slits changes. This can lead to a shift in the position of the central maximum, as the waves may no longer arrive at the screen in phase, depending on the exact distance moved.
• Fringe Spacing: The overall spacing of the interference fringes may also change. If the source is significantly closer to one slit, the angle at which the light waves meet the screen will alter, potentially leading to a more compressed or expanded fringe pattern.

Understanding the Central Maximum Shift

The central maximum is defined as the point where the path lengths from both slits to the screen are equal. When the source is moved closer to one slit, the light waves from that slit will have a shorter path to the screen compared to the waves from the other slit. This can lead to a scenario where:

• The central maximum may shift slightly towards the slit that is closer to the light source.
• The overall interference pattern may become less distinct if the intensity difference between the two slits becomes too great, potentially leading to a dominant bright fringe at the position of the closer slit.

Example Scenario

Imagine you have a flashlight illuminating two slits, and you move the flashlight closer to the left slit. The light from the left slit will now be more intense and reach the screen faster than the light from the right slit. As a result, the central maximum will likely shift towards the left, and the bright fringe pattern may become skewed, with the left side appearing brighter than the right.

Conclusion

In summary, moving the light source closer to one of the slits in Young's double-slit experiment alters the intensity and potentially the position of the central maximum. This shift occurs due to changes in path length and intensity, leading to a modified interference pattern. Understanding these dynamics is crucial for grasping the principles of wave interference and the behavior of light.