NEET UG · Physics · Waves

Standing Waves, Organ Pipes and Beats: NEET previous year questions

7 questions in ten years of NEET, in 6 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 7; about 0.7 per paper
Years asked: 6/10; last asked 2026
Chance of a question next paper: 50%; historical rate, how we compute it
Weighted estimate: 0.7; model; history: 0.7 a paper on average, typically 0–1

Key findings

01
Asked in 6 of 10 papers, 7 questions in all: #120 of 204 topics by ten-year total. It comes back every 1.8 years on average.
02
67% of its questions since 2018 tested an idea never asked before; none repeated an idea from the year before.
03
The most repeated idea is Open Organ Pipe Harmonics, asked 3 times (2018, 2023, 2025), usually as “numerical”.
04
NEET has asked 0 of the 5 ideas in this topic; 0 have never been asked, directly or indirectly.
05
Mostly asked as numerical (71%); 14% easy, 0% hard.

Questions per year

Up to 2023: 0.7; per paper
Since 2024: 0.7; -0.0
Usual gap: 1.8 yrs; between papers asking it
Swing: ±0.6; questions, year to year

How it is asked

Difficulty, format and skill

Across all 7 questions on Standing Waves, Organ Pipes and Beats since 2017.

Difficulty

QUESTIONS

Easy1 · 14%
Medium6 · 86%
Hard0 · 0%

Format

Numerical · 5 Q71%
One-line MCQ · 2 Q29%

Skill tested

Calculation · 3 Q43%
Application · 2 Q29%
Concept · 1 Q14%
Multi-step · 1 Q14%

Repeats

New idea, or one asked before?

Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.

’17’18’19’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier paper

Coverage of the topic

NEET has asked 0 of the 5 ideas in this topic. 0 have never been asked yet.

Asked directly0 · 0%
Touched inside another question5 · 100%
Never asked0 · 0%

Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.

Drill down

Idea, year, question

Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.

ideaAskedShareYears’17’18’19’20’21’22’23’24’25’26

Repeated3 · 43%43%3/10
- 2025 · Q45
  A pipe open at both ends has a fundamental frequency $f$ in air. The pipe is now dipped vertically in a water drum to half of its length.…
  mediumOne-line MCQ
- 2023 · Q14
  The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is :
  easyOne-line MCQ
- 2018 · Q2
  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…
  mediumNumericalNew idea
1 · 14%14%1/10
1 · 14%14%1/10
1 · 14%14%1/10
1 · 14%14%1/10

Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.

Ideas

Every idea inside this topic

5 different ideas were tested; 1 came more than once.

Open Organ Pipe Harmonics3×
numerical
One-line MCQ · 6% next
Nodes and Antinodes1×
numerical
Numerical · 6% next
Beats and String Tension1×
numerical
Numerical · 4% next
Resonance Tube1×
numerical
Numerical · 4% next
Closed Organ Pipe Harmonics1×
numerical
Numerical · 4% next

Idea	Times	Format	Chance next	Foundation for
Open Organ Pipe Harmonicsnumerical	3	One-line MCQApplication	6%	–
Nodes and Antinodesnumerical	1	NumericalConcept	6%	–
Beats and String Tensionnumerical	1	NumericalMulti-step	4%	–
Resonance Tubenumerical	1	NumericalCalculation	4%	–
Closed Organ Pipe Harmonicsnumerical	1	NumericalCalculation	4%	–

Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. All repeated ideas

Every question

Standing Waves, Organ Pipes and Beats questions, year by year

The opening words of each question as it appeared in the official paper, with the idea it tested.

NEET 20261 question

Q4
For sound waves, if the number of nodes for the 5 $^{th}$ harmonic of an open-ended pipe is n and that for the 9 $^{th}$ harmonic of the…
Idea: Nodes and Antinodes
New ideaMediumNumerical

NEET 20251 question

Q45
A pipe open at both ends has a fundamental frequency $f$ in air. The pipe is now dipped vertically in a water drum to half of its length.…
Idea: Open Organ Pipe Harmonics
MediumOne-line MCQ

NEET 20231 question

Q14
The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is :
Idea: Open Organ Pipe Harmonics
EasyOne-line MCQ

NEET 20201 question

Q147
In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency 6 Hz. When tension in B is…
Idea: Beats and String Tension
New ideaMediumNumerical

NEET 20182 questions

Q2
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…
Idea: Open Organ Pipe Harmonics
New ideaMediumNumerical
Q24
A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable…
Idea: Resonance Tube
New ideaMediumNumerical

NEET 20171 question

Q43
The two nearest harmonics of a tube closed at one end and open at other end are 220 Hz and 260 Hz. What is the fundamental frequency of…
Idea: Closed Organ Pipe Harmonics
MediumNumerical

Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.