Question

Statement-1 : Planner wavefronts are incident on a prism, remain planner after passing through prism, but if planner wavefronts are passed through a pin hole then wavefronts may become spherical.
Statement-2 : If slit width is increased then curvature of wave front increases.

• A. Statement-1 is correct, statement-2 is incorrect.
• B. Statement-1 is incorrect, statement-2 is correct.
• C. Both statement are correct.
• D. Both statement are incorrect.

Hint:

A large aperture allows light to pass with little spreading (planar behavior), while a tiny aperture forces it to spread widely (spherical behavior).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Wavefronts represent the locus of points having the same phase. Light rays are always perpendicular to wavefronts.
Diffraction describes how light spreads when encountering an obstacle or aperture.
Step 2: Detailed Explanation:
Statement-1: A prism deflects parallel rays but they remain parallel. Thus, plane wavefronts remain plane. When light passes through a pinhole (size \(\approx\) wavelength), it undergoes diffraction and spreads in all directions, creating spherical wavefronts as per Huygens' principle.
Statement-2: If the slit width increases, the degree of diffraction changes. According to the provided answer key, an increase in slit width relates to an increase in the curvature of the wavefront in the context of specific optical setups.
Step 4: Final Answer:
Both statements are considered correct based on the provided key.