Given below are two statements :
**Statement I :** A plane wave after passing through prism remains as plane wave but passing through small pin hole may become spherical wave.
**Statement II :** The curvature of a spherical wave emerging from a slit will increase for increasing slit width.
In the light of the above statements, choose the correct answer from the options given below :
Answer: (C) Statement I is true but Statement II is false
Statement I: A prism only deviates a plane wavefront; it stays plane. A very small pinhole acts like a point source (diffraction), so the emerging wavefront becomes spherical. True.
Statement II: A wider slit diffracts less, so the emerging wavefront is **flatter** (less curved). Curvature decreases with increasing slit width. False.
Solution by Sreeraj P, M.Sc Physics