Question

Assertion: If a person wants to observe sharp and clear fringes of good contrast, then, interference experiment is preferable compared to diffraction

Reason: In diffraction, intensity after the central maximum decreases rapidly, so fringe pattern become blurred.

• A. The assertion is true, but the reason is false
• B. Both the assertion and reason are false
• C. Both Assertion and reason are true, but the reason is not the correct explanation of the assertion.
• D. Both Assertion and reason are true, and the reason is the correct explanation of the assertion.

Answer 1

The correct option is D Both Assertion and reason are true, and the reason is the correct explanation of the assertion.

We know that, in diffraction pattern, the central has the maximum intensity $\left(I_0\right)$ and intensity starts decreasing rapidly.

Intensity of first maximum is approximately $\left(\frac{I_0}{22}\right)$

Intensity of second maximum is approximately $\left(\frac{I_0}{62}\right)$.

In interference pattern, almost all the bright fringes including central bright fringe will be at the same intensity.

So, If a person wants to observe sharp and clear fringes of good contrast, then, interference experiment is preferable compared to diffraction.

Hence, option $\left(A\right)$ is correct.