NEET UG 2018 · Physics · Question 9
NEET 2018 Physics, question 9
Question 9 of the NEET 2018 paper (code AA) is a Physics question from Wave Optics. Its idea, Angular Fringe Width, was asked twice, in 2018 and 2023, across NEET 2017–2026. The CBSE official answer key gives option 2.
Updated 2026-10-08
Q9 · Physics
In Young's double slit experiment the separation d between the slits is 2 mm, the wavelength of the light used is 5896 Å and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20°. To increase the fringe angular width to 0.21° (with same and D) the separation between the slits needs to be changed to
- 12.1 mm
- 21.9 mmOfficial answer
- 31.8 mm
- 41.7 mm
Official answer: option 2 · CBSE official answer key
Same idea
Angular Fringe Width, in other papers
NEET asked this idea twice, in 2018 and 2023. The other question below.
- 2023 Q24For Young's double slit experiment, two statements are given below: Statement I : If screen is moved away from the plane of slits, angular…Two statements · Medium
The chapter
Wave Optics in ten years of NEET
15 questions from 2017–2026, asked in 8 of 10 papers, about 1.5 a paper. Young's Double Slit alone had 7.