What does Oscillations and Waves cover for NEET Physics?

16 lessons: Beats, Energy in SHM, Fundamental Mode Harmonics, Longitudinal Transverse Waves, Periodic Motion, Progressive Wave Displacement, Restoring Force Constant, SHM Equation, SHM Phase, Simple Pendulum, Speed Travelling Wave, Spring Oscillations, Standing Waves Strings Pipes, Superposition Reflection Waves, Time Period Frequency and Wave Motion.

How often has Oscillations and Waves come up in NEET past papers?

Our set of verified past papers has 14 questions from this unit, from NEET 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Each is answered against the official NTA key.

Is the Oscillations and Waves material free?

Yes. All 16 lessons and 128 practice questions are free, with no login needed.

Oscillations and Waves

16 lessons

Topic index in NCERT order

16 of 16 lessons by the NCERT chapter they teach from, in book order. The page is the first printed page of your NCERT book the lesson cites; PYQs are the past NEET questions on that topic.

Class 11 Physics, Chapter 13

Periodic Motionp. 2600 PYQs
SHM Equationp. 2603 PYQs
SHM Phasep. 2601 PYQ
Time Period Frequencyp. 2600 PYQs
Energy in SHMp. 2670 PYQs
Simple Pendulump. 2712 PYQs
Restoring Force Constantp. 2721 PYQ
Spring Oscillationsp. 2722 PYQs

Class 11 Physics, Chapter 14

Wave Motionp. 2780 PYQs
Longitudinal Transverse Wavesp. 2800 PYQs
Progressive Wave Displacementp. 2810 PYQs
Speed Travelling Wavep. 2851 PYQ
Superposition Reflection Wavesp. 2870 PYQs
Fundamental Mode Harmonicsp. 2910 PYQs
Standing Waves Strings Pipesp. 2913 PYQs
Beatsp. 2941 PYQ

Beats

8 MCQs1 PYQs1 revision cardWorked example

Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

Energy in SHM

8 MCQs3 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Fundamental Mode Harmonics

8 MCQs4 revision cardsWorked example

Direct Application (3)Easy Recall (3)Calculation (2)

Longitudinal Transverse Waves

8 MCQs3 revision cardsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

Periodic Motion

8 MCQs5 revision cardsWorked example

Concept Trap (1)Easy Recall (2)Direct Application (3)Calculation (2)

Progressive Wave Displacement

8 MCQs6 revision cardsWorked example

Calculation (2)Easy Recall (3)Direct Application (3)

Restoring Force Constant

8 MCQs1 PYQs5 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

SHM Equation

8 MCQs3 PYQs5 revision cardsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (2)

SHM Phase

8 MCQs1 PYQs1 revision cardWorked example

Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

Simple Pendulum

8 MCQs2 PYQs5 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (1)Concept Trap (1)

Speed Travelling Wave

8 MCQs1 PYQs8 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Spring Oscillations

8 MCQs2 PYQs6 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Standing Waves Strings Pipes

8 MCQs3 PYQs4 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (2)

Superposition Reflection Waves

8 MCQs3 revision cardsWorked example

Easy Recall (4)Direct Application (2)Concept Trap (1)Calculation (1)

Time Period Frequency

8 MCQs3 revision cardsWorked example

Easy Recall (2)Direct Application (4)Calculation (2)

Wave Motion

8 MCQs3 revision cardsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (2)

Past-paper questions from this unit

14 questions from NEET 2020, 2021, 2022, 2023, 2024, 2025, 2026. Answers verified against NTA official keys.

By year in our set: 2020 (2) · 2021 (1) · 2022 (2) · 2023 (2) · 2024 (2) · 2025 (2) · 2026 (3)

Lesson: Standing Waves Strings Pipes

NEET 2026

For sound waves, if the number of nodes for the 5th harmonic of an open-ended pipe is n and that for the 9th harmonic of the same pipe with one of its ends closed is m, the ratio n/m is :

15/9

29/5

43/5

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: Restoring Force Constant

NEET 2026

A cylindrical cork of uniform density floats in a liquid of density ρ₁. If the cork is depressed slightly and released, it oscillates harmonically with time period T. If the same cork floats in another liquid of density ρ₂, then the similar oscillation has time period 2T. The value of ρ₂/ρ₁ is :

31/2

41/4

NTA Answer: Option 4(final)

Report an error · Every fix is public: corrections log

Lesson: SHM Equation

NEET 2026

Consider a spring-mass simple harmonic oscillator in one dimension. The mass of the particle is m kg and the spring constant is k Nm⁻¹. At a given instant, the extension of the spring is x meter and the speed of the particle is v ms⁻¹. On the x-v plane, if the graph of v as a function of x is a circle, then the correct option is :

1k = 1/m

2k = m

3k = m²

4k = √m

NTA Answer: Option 2(final)

Report an error · Every fix is public: corrections log

Lesson: Standing Waves Strings Pipes

NEET 2025

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. The fundamental frequency of the air column is now equal to:

12f

2f/2

43f/2

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: Spring Oscillations

NEET 2025

Two identical point masses P and Q, suspended from two separate massless springs of spring constants k₁ and k₂, respectively, oscillate vertically. If their maximum speeds are the same, the ratio (A_Q/A_P) of the amplitude A_Q of mass Q to the amplitude A_P of mass P is

1√(k₁/k₂)

2k₂/k₁

3k₁/k₂

4√(k₂/k₁)

NTA Answer: Option 1(final)

Report an error · Every fix is public: corrections log

Lesson: SHM Equation

NEET 2024Revised key

If x = 5 sin(πt + π/3) m represents the motion of a particle executing simple harmonic motion, the amplitude and time period of motion, respectively, are

15 cm, 2 s

25 m, 2 s

35 cm, 1 s

45 m, 1 s

NTA Answer: Option 2(revised_final)

Report an error · Every fix is public: corrections log

Lesson: Simple Pendulum

NEET 2024Revised key

If the mass of the bob in a simple pendulum is increased to thrice its original mass and its length is made half its original length, then the new time period of oscillation is x/2 times its original time period. Then the value of x is:

1√3

2√2

32√3

NTA Answer: Option 2(revised_final)

Report an error · Every fix is public: corrections log

Lesson: Standing Waves Strings Pipes

NEET 2023

The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is

12 : 1

21 : 3

33 : 1

41 : 2

NTA Answer: Option 1(final)

Report an error · Every fix is public: corrections log

Lesson: SHM Equation

NEET 2023

The x-t graph of a particle performing simple harmonic motion is shown in the figure. The acceleration of the particle at t = 2 s is

1−(π²/8) m s⁻²

2(π²/16) m s⁻²

3−(π²/16) m s⁻²

4(π²/8) m s⁻²

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: Speed Travelling Wave

NEET 2022

If the initial tension on a stretched string is doubled, then the ratio of the initial and final speeds of a transverse wave along the string is

11 : 2

21 : 1

3√2 : 1

41 : √2

NTA Answer: Option 4(final)

Report an error · Every fix is public: corrections log

Lesson: Simple Pendulum

NEET 2022

Two pendulums of length 121 cm and 100 cm start vibrating in phase. At some instant, the two are at their mean position in the same phase. The minimum number of vibrations of the shorter pendulum after which the two are again in phase at the mean position is:

211

410

NTA Answer: Option 2(final)

Report an error · Every fix is public: corrections log

Lesson: Spring Oscillations

NEET 2021

A spring is stretched by 5 cm by a force 10 N. The time period of the oscillations when a mass of 2 kg is suspended by it is

10.628 s

20.0628 s

36.28 s

43.14 s

NTA Answer: Option 1(final)

Report an error · Every fix is public: corrections log

Lesson: Beats

NEET 2020

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 slightly decreased, the beat frequency increases to 7 Hz. If the frequency of A is 530 Hz, the original frequency of B will be :

1537 Hz

2523 Hz

3524 Hz

4536 Hz

NTA Answer: Option 3(final)

Report an error · Every fix is public: corrections log

Lesson: SHM Phase

NEET 2020

The phase difference between displacement and acceleration of a particle in a simple harmonic motion is :

1zero

2π rad

33π/2 rad

4π/2 rad

NTA Answer: Option 2(final)

Report an error · Every fix is public: corrections log

Exam traps and common mistakes in this unit

Lesson: SHM Equation

Trap

SHM period: amplitude dependence claim

Category: Overthinking

Student claims SHM period depends on amplitude. For ideal SHM (Hooke's law spring or simple pendulum at small angle), period is INDEPENDENT of amplitude.

When it triggers

Question gives changes in amplitude and asks for new period.

How to avoid

T = 2π√(m/k) (spring) or 2π√(L/g) (pendulum, small angle) — neither depends on A. Only at large pendulum angles does T pick up a small amplitude correction.

Lesson: Simple Pendulum

Trap

Pendulum: mass-dependence claim

Category: Overthinking

Student writes T as depending on bob mass. Simple pendulum T = 2π√(L/g); independent of m.

When it triggers

Question changes pendulum bob mass and asks for new period.

How to avoid

Mass cancels in derivation (gravitational mass = inertial mass). Mass changes the bob's KE and PE proportionally; period unaffected.

Lesson: Standing Waves Strings Pipes

Trap

Pipe harmonics: open vs closed end

Category: Similar Terms

Student includes even harmonics in a closed-end pipe. Closed pipe has only ODD harmonics (f, 3f, 5f, ...).

When it triggers

Question describes pipe closed at one end (e.g. resonance tube).

How to avoid

Open both ends: all harmonics, f_n = nv/(2L). Closed one end: odd only, f_n = (2n-1)v/(4L). Fundamental of closed pipe is HALF that of open pipe of same L.

Lesson: SHM Equation

Mistake

Claims SHM period depends on amplitude.

Root cause: concept gap

Correction

Ideal SHM: T = 2π√(m/k) (spring) or 2π√(L/g) (pendulum, small angle) — no amplitude dependence. Doubling amplitude does not change period.

Lesson: Simple Pendulum

Mistake

Includes bob mass in simple pendulum period formula.

Root cause: concept gap

Correction

Simple pendulum T = 2π√(L/g) — independent of mass. Equivalence of inertial and gravitational mass cancels m.

Lesson: Standing Waves Strings Pipes

Mistake

Includes even harmonics in a closed-end pipe.

Root cause: concept gap

Correction

Closed-end pipe has only ODD harmonics (f, 3f, 5f, ...). Open-both-ends pipe has all (f, 2f, 3f, ...). Reason: closed end has displacement node and pressure antinode.

Formulas in this unit

Lesson: Beats

Beat frequency

f_{beat} = ∣ f_{1} - f_{2} ∣

When two waves of nearly equal frequencies superpose, amplitude oscillates at the difference frequency.

Symbol	Quantity	SI Unit
f_beat	beat frequency	Hz
f1, f2	superposed frequencies	Hz

Valid when

Linear superposition
f1, f2 close in value

Lesson: Energy in SHM

Total energy in SHM

E = \frac{1}{2} k A^{2} = \frac{1}{2} m ω^{2} A^{2}

Total mechanical energy is constant. Oscillates between KE (max at x=0) and PE (max at x=±A).

Symbol	Quantity	SI Unit
E	total energy	J
k	spring constant	N/m
A	amplitude	m
m	mass	kg
omega	angular frequency	rad/s

Valid when

Conservative SHM (no damping)
Elastic regime

Lesson: Fundamental Mode Harmonics

Standing wave frequencies on fixed-fixed string

f_{n} = \frac{n v}{2 L}

Allowed frequencies on string fixed at both ends. n=1 fundamental; harmonics 2f, 3f, ...

Symbol	Quantity	SI Unit
f_n	n-th harmonic	Hz
v	wave speed on string	m/s
L	string length	m
n	harmonic number	-

Valid when

String fixed at both ends
Wave speed v as defined above

Lesson: Longitudinal Transverse Waves

Wave speed on string

v = \frac{T}{μ}

Speed of transverse wave on string under tension T, linear mass density mu.

Symbol	Quantity	SI Unit
v	wave speed	m/s
T	tension	N
mu	linear mass density	kg/m

Valid when

Stretched uniform string
Small amplitude

Lesson: Restoring Force Constant

Period of mass-spring oscillator

T = 2 π \frac{m}{k}

Period of horizontal spring with mass m, spring constant k. Independent of amplitude.

Symbol	Quantity	SI Unit
T	period	s
m	mass	kg
k	spring constant	N/m

Valid when

Hooke's law spring
No damping
Small enough amplitude to stay in elastic regime

Lesson: SHM Equation

SHM displacement

x (t) = A cos (ω t + ϕ); ω = 2 π f

Displacement in simple harmonic motion. Velocity = -A*omega*sin(omega*t+phi); a = -omega^2 * x.

Symbol	Quantity	SI Unit
A	amplitude	m
omega	angular frequency	rad/s
phi	phase	rad
T	period	s
f	frequency	Hz

Valid when

Restoring force linear (F = -kx)
No damping

Lesson: Simple Pendulum

Period of simple pendulum (small angle)

T = 2 π \frac{L}{g}

Period of simple pendulum of length L. Holds for small amplitudes (sin theta ~ theta).

Symbol	Quantity	SI Unit
T	period	s
L	pendulum length	m
g	gravity	m/s^2

Valid when

Small angular amplitude (typically <15°)
Massless string
Point bob

Lesson: Speed Travelling Wave

Speed of sound in gas (Newton-Laplace)

v = \frac{γ P}{ρ}

Speed of sound in gas. Adiabatic index gamma, pressure P, density rho. Increases with sqrt(T).

Symbol	Quantity	SI Unit
v	speed of sound	m/s
gamma	adiabatic index	-
P	pressure	Pa
rho	density	kg/m^3

Valid when

Ideal gas
Adiabatic compression/expansion of sound waves

Lesson: Standing Waves Strings Pipes

Standing wave in closed-end pipe

f_{n} = \frac{( 2 n - 1 ) v}{4 L}

Pipe closed at one end has only odd harmonics: f, 3f, 5f, ...

Symbol	Quantity	SI Unit
f_n	n-th harmonic	Hz
v	sound speed	m/s
L	pipe length	m

Valid when

Closed at one end (open at other)
End correction neglected

Lesson: Standing Waves Strings Pipes

Standing wave in open-open pipe

f_{n} = \frac{n v}{2 L}

Pipe open at both ends has all harmonics. Same formula as string.

Symbol	Quantity	SI Unit
f_n	n-th harmonic	Hz
v	sound speed	m/s
L	pipe length	m

Valid when

Open at both ends
End correction neglected

NEET question patterns in this unit

Lesson: Beats

Two strings/forks slightly out of tune produce beats; find one frequency given the other and beat frequency.

Direct ApplicationEasy

Common distractors

treats beat as sum

Adds frequencies instead of subtracting

Lesson: Fundamental Mode Harmonics

Open-open pipe (all harmonics) vs closed-end pipe (odd only). Compare frequency ratios.

InterpretationMedium

Common distractors

treats closed pipe like open

Includes even harmonics in closed pipe

Lesson: Longitudinal Transverse Waves

Given tension change, find new wave speed on string. v ∝ sqrt(T).

Direct ApplicationEasy

Common distractors

uses linear tension scaling

Treats v ∝ T not sqrt(T)

Lesson: Restoring Force Constant

Given spring extension/compression with given force, find k, then find period when given mass m. T = 2pisqrt(m/k).

Multi StepEasy

Common distractors

forgets 2pi factor

Drops 2*pi

uses amplitude in period

Believes T depends on amplitude

Lesson: SHM Equation

Phase between displacement, velocity, acceleration in SHM. v leads x by π/2; a leads x by π.

InterpretationEasy

Common distractors

uses pi 2 instead of pi

Confuses v-x phase with a-x phase

Lesson: Simple Pendulum

Given pendulum length and g, find T. Or given mass change, observe T unchanged.

Direct ApplicationEasy

Common distractors

expects mass dependence

Assumes T depends on bob mass

Questions about this unit

What does Oscillations and Waves cover for NEET Physics?: 16 lessons: Beats, Energy in SHM, Fundamental Mode Harmonics, Longitudinal Transverse Waves, Periodic Motion, Progressive Wave Displacement, Restoring Force Constant, SHM Equation, SHM Phase, Simple Pendulum, Speed Travelling Wave, Spring Oscillations, Standing Waves Strings Pipes, Superposition Reflection Waves, Time Period Frequency and Wave Motion.
How often has Oscillations and Waves come up in NEET past papers?: Our set of verified past papers has 14 questions from this unit, from NEET 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Each is answered against the official NTA key.
Is the Oscillations and Waves material free?: Yes. All 16 lessons and 128 practice questions are free, with no login needed.