Final answer:
Interference experiments produce sharp and clear fringes, while diffraction patterns can also remain sharp, especially in diffraction gratings. The correct answer is that both the assertion and reason are true, but the reason does not fully explain the assertion.
"The correct option is approximately option B"
Step-by-step explanation:
The question asks which experimental method is preferable for observing sharp and clear fringe patterns: interference experiments or diffraction. The assertion is that an interference experiment, such as Young's double-slit experiment, is preferable for observing sharp and clear fringes. This assertion is true, as interference experiments generally produce fringe patterns with good contrast due to constructive and destructive interference of light waves from narrow slits or openings.
The reason given is that in diffraction, the intensity after the central maximum drops rapidly, leading to a blurred fringe pattern. While it's true that the intensity decreases in diffraction patterns, particularly in single-slit diffraction where the central maximum is the brightest and sharpness reduces in subsequent maxima, in the context of a diffraction grating, which is essentially an extended version of the double-slit experiment with many slits, the fringe patterns remain sharp and clear. Moreover, diffraction gratings can also result in very sharp maxima, which maintains the contrast of the fringes. Therefore, the reason is not completely accurate as it oversimplifies the behavior of diffraction patterns and does not account for the behavior of a diffraction grating.
Therefore, the correct answer to this question is 'B. Both Assertion and reason are true, but the reason is not the correct explanation of the assertion.'