1. Measurement Errors Ruler or Scale Precision: Limited precision when measuring fringe spacing, slit separation, or distance from slits to the screen introduces error. Parallax Error: Misreading the position of fringes due to the angle of sight. Fringe Visibility: Difficulty distinguishing the exact center of fringes or blurring of fringes can lead to inaccurate position measurement. 2. Experimental Setup Issues Alignment Errors: The slits, laser, and screen may not be perfectly parallel or perpendicular, causing a shift in the pattern. Screen Movement: The screen may move slightly during the experiment, altering the measured distances. 3. Light Source Issues Non-monochromatic Light: If the light source is not truly monochromatic, multiple wavelengths can interfere, making the pattern less distinct. Coherence: Light needs to be coherent for clear interference patternspartial coherence reduces pattern sharpness. 4. Slit and Apparatus Quality Irregular Slit Spacing or Width: Manufacturing imperfections in the slits can affect the spacing or width, altering the expected pattern. Finite Slit Width Effects: Wide slits affect the pattern and may overlap with interference effects. 5. Environmental Factors Vibrations and Air Currents: Causes movement and blurring of the pattern. Ambient Light: External light sources can make the pattern harder to see clearly