JEE Main 202628 JanuaryMorning Shift
- Exam
- JEE Main
- Year
- 2026
- Date
- 28 January
- Shift
- Morning Shift
- Subject
- Physics
- Chapter
- Wave Optics
JEE Main 2026 · 28 January · Morning Shift · Physics · Wave Optics
Given below are two statements: Statement I : A plane wave after...
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
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
Options
- ABoth Statement I and Statement II are true
- BStatement I is false but Statement II is true
- CBoth Statement I and Statement II are false
- DStatement I is true but Statement II is false
Correct answer
D. Statement I is true but Statement II is false
Step-by-step solution
Statement I: A plane wave passing through a prism remains a plane wave due to refraction at parallel surfaces. However, when passing through a small pin hole comparable to the wavelength, Huygens' principle applies where each point on the wavefront acts as a source of secondary wavelets, creating a spherical wavefront. Statement I is TRUE.
Statement II: When a spherical wave emerges from a slit, the diffraction effect depends on slit width. A narrower slit causes stronger diffraction and greater curvature of the emerging wavefront. As slit width increases, diffraction effects decrease and the wavefront becomes flatter with reduced curvature. Therefore, the curvature decreases with increasing slit width. Statement II is FALSE.
The correct answer identifies that Statement I is true but Statement II is false.
Statement II: When a spherical wave emerges from a slit, the diffraction effect depends on slit width. A narrower slit causes stronger diffraction and greater curvature of the emerging wavefront. As slit width increases, diffraction effects decrease and the wavefront becomes flatter with reduced curvature. Therefore, the curvature decreases with increasing slit width. Statement II is FALSE.
The correct answer identifies that Statement I is true but Statement II is false.