NEET UG 2018 · Physics · Question 2
NEET 2018 Physics, question 2
Question 2 of the NEET 2018 paper (code AA) is a Physics question from Waves. Its idea, Open Organ Pipe Harmonics, was asked 3 times, in 2018, 2023 and 2025, across NEET 2017–2026. The CBSE official answer key gives option 3.
Updated 2026-10-08
Q2 · Physics
The fundamental frequency in an open organ pipe is equal to the third harmonic of a closed organ pipe. If the length of the closed organ pipe is 20 cm, the length of the open organ pipe is
- 112.5 cm
- 28 cm
- 313.2 cmOfficial answer
- 416 cm
Official answer: option 3 · CBSE official answer key
Same idea
Open Organ Pipe Harmonics, in other papers
NEET asked this idea 3 times, in 2018, 2023 and 2025. The other 2 questions below.
- 2025 Q45A pipe open at both ends has a fundamental frequency in air. The pipe is now dipped vertically in a water drum to half of its length.…One-line MCQ · Medium
- 2023 Q14The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is :One-line MCQ · Easy
Open Organ Pipe Harmonics: every question and how it was framed
The chapter
Waves in ten years of NEET
9 questions from 2017–2026, asked in 7 of 10 papers, about 0.9 a paper. Standing Waves, Organ Pipes and Beats alone had 7.