NEET-UG SERIES

Physics

Waves

67 previous year questions.

Volume: 67 Ques

Yield: High

High-Yield Trend

1

2024

2

2023

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2020

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2011

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Chapter Questions
67 MCQs

01

PYQ 1988

medium

physics ID: neet-ug-

The velocity of sound in any gas depends upon

1

wavelength of sound only

2

density and elasticity of gas

3

intensity of sound waves only

4

amplitude and frequency of sound

02

PYQ 1989

medium

physics ID: neet-ug-

A metre length of string has a mass of . If the tension in the string in, the speed of a wave on the string is

1

2

3

4

03

PYQ 1989

medium

physics ID: neet-ug-

If the amplitude of sound is doubled and the frequency reduced to one fourth, the intensity of sound at the same point will be

1

increasing by a factor of 2

2

decreasing by a factor of 2

3

decreasing by a factor of 1/4

4

unchanged

04

PYQ 1990

medium

physics ID: neet-ug-

Velocity of sound waves in air is 330 m/s. For a particular sound wave in air, a path difference of 40 cm is equivalent to phase difference of . The frequency of this wave

1

165 Hz

2

150 Hz

3

660 Hz

4

330 Hz

05

PYQ 1991

medium

physics ID: neet-ug-

A closed organ pipe (closed at one end) is excited to support the third overtone. It is found that air in the pipe has

1

three nodes and three antinodes

2

three nodes and four antinodes

3

four nodes and three antinodes

4

four nodes and four antinodes

06

PYQ 1991

medium

physics ID: neet-ug-

Two trains move towards each other with the same speed. The speed of sound is 340 m/s. If the height of the tone of the whistle of one of them heard on the other changes to 9/8 times, then the speed of each train should be

1

20 m/s

2

2 m/s

3

200 m/s

4

2000 m/s

07

PYQ 1991

medium

physics ID: neet-ug-

Ratio of intensities of two waves are given by 4 : 1. Then ratio of the amplitudes of the two waves is

1

2 : 1

2

1 : 2

3

4: 1

4

1:4

08

PYQ 1992

medium

physics ID: neet-ug-

The frequency of sinusodial wave y = 0.40cos [2000 t + 0.80] would be

1

2

3

4

09

PYQ 1992

medium

physics ID: neet-ug-

With the propogation of a longitudinal wave through a material medium, the quantities transmitted in the propogation direction are

1

energy, momentum and mass

2

energy

3

energy and mass

4

energy and linear momentum

10

PYQ 1992

medium

physics ID: neet-ug-

For production of beats the two sources must have

1

different frequencies and same amplitude

2

different frequencies

3

different frequencies, same amplitude and same phase

4

different frequencies and same phase

11

PYQ 1993

medium

physics ID: neet-ug-

Wave has simple harmonic motion whose period is 4 seconds while another wave which also possesses simple harmonic motion has its period 3 sec. If both are combined, then the resultant wave will have the period equal to

1

4 sec

2

5 sec

3

12 sec

4

3 sec

12

PYQ 1994

easy

physics ID: neet-ug-

A wave of frequency 100 Hz travels along a string towards its fixed end. When this wave travels back, after reflection, a node is formed at a distance of 10 cm from the fixed end. The speed of the wave (incident and reflected) is

1

20 m/s

2

40 m/s

3

5 m/s

4

10 m/s

13

PYQ 1995

medium

physics ID: neet-ug-

A star, which is emitting radiation at a wavelength of is approaching the earth with a velocity of The change in wavelength of the radiation as received on the earth is

1

2

3

zero

4

14

PYQ 1995

medium

physics ID: neet-ug-

A source of sound gives 5 beats per second, when sounded with another source of frequency The second harmonic of the source, together with a source of frequency gives 5 beats per second. What is the frequency of the source?

1

2

3

4

15

PYQ 1998

easy

physics ID: neet-ug-

A vehicle, with a horn of frequency n is moving with a velocity of 30 m/s in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency . Then (if the sound velocity in air is 300 m/s)

1

2

3

4

16

PYQ 1998

medium

physics ID: neet-ug-

A standing wave having 3 nodes and 2 antinodes is formed between two atoms having a distance between them. The wavelength of the standing wave is

1

2

3

4

17

PYQ 1998

medium

physics ID: neet-ug-

A transverse wave is represented by the equation For what value of, is the maximum particle velocity equal to two times the wave velocity?

1

2

3

4

18

PYQ 2000

medium

physics ID: neet-ug-

The equations of two waves acting in perpendicular directions are given as and where the resultant wave represents

1

a circle (c.w)

2

a circle (a.c.w)

3

an Ellipse (c.w)

4

an ellipse (a.c.w)

19

PYQ 2000

medium

physics ID: neet-ug-

A string is cut into three parts, having fundamental frequencies n 1, n 2, and n 3 respectively. Then original fundamental frequency ‘n’ related by the expression as:

1

2

3

4

20

PYQ 2000

medium

physics ID: neet-ug-

The equations of two waves given as and, Where, then resultant wave represent:

1

a circle (c.w)

2

a circle (a.c.w)

3

an Ellipse (c.w)

4

an ellipse (a.c.w)

21

PYQ 2000

medium

physics ID: neet-ug-

Two stationary sources each emitting waves of wave length . An observer moves from one source to other with velocity . Then number of beats heard by him:

1

2

3

4

22

PYQ 2001

medium

physics ID: neet-ug-

Two waves having equation If in the resultant wave the frequency and amplitude remain equal to amplitude of superimposing waves, the phase difference between them is

1

2

3

4

23

PYQ 2001

medium

physics ID: neet-ug-

If the tension and diameter of a sonometer wire of fundamental frequency n is doubled and density is halved then its fundamental frequency will become

1

2

3

n

4

24

PYQ 2001

medium

physics ID: neet-ug-

The equation of a wae is represented by then the velocity of wave will be

1

100 m/s

2

4 m/s

3

1000 m/s

4

10 m/s

25

PYQ 2002

medium

physics ID: neet-ug-

A whistle revolves in a circle with angular speed using a string of length 50 cm. If the frequency of sound from the whistle is 385 Hz, then what is the minimum frequency heard by an observer which is far away from the centre :-

1

385 Hz

2

374 Hz

3

394 Hz

4

333 Hz

26

PYQ 2002

medium

physics ID: neet-ug-

A wave travelling in positive X-direction with a = 0.2 mt., velocity = 360 mt/sec. and then correct expression for the wave is:-

1

2

3

4

27

PYQ 2003

medium

physics ID: neet-ug-

An observer moves towards a stationary source of sound with a speed of the speed of sound. The wavelength and frequency of the source emitted are λ and f respectively. The apparent frequency and wavelength recorded by the observer are respectively:

1

1.2f, 1.2λ

2

1.2f, λ

3

f, 1.2λ

4

0.8f, 0.8λ

28

PYQ 2004

medium

physics ID: neet-ug-

The phase difference between two waves, represented by y 1 = 10 -6 sin {100t + () + 0.5}m y 2 = 10 -6 cos{100t + ()}m Where X is expressed in meters and t is expressed in seconds, is approximately

1

2.07 radians

2

0.5 radians

3

1.5 radians

4

1.07 radians

29

PYQ 2004

medium

physics ID: neet-ug-

A car is moving towards a high cliff. The car driver sounds a horn of the frequency 'f'. The reflected sound heard by the driver has a frequency of 2f. If 'v' is the velocity of sound then the velocity of the car, in the same velocity\ units, will be

1

2

3

4

30

PYQ 2005

easy

physics ID: neet-ug-

Two vibrating tuning forks produce progressive waves given by y 1 =4 sin 500 t and y 2 =2 sin 506 t. Number of beats produced per minute is:

1

360

2

180

3

120

4

30

31

PYQ 2005

medium

physics ID: neet-ug-

A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distances of 2 m and 3 m respectively from the source. The ratio of the intensities of the waves at P and Q is

1

3 : 2

2

2 : 3

3

9 : 4

4

4 : 9

32

PYQ 2006

medium

physics ID: neet-ug-

The time of reverberation of a room A is one second. What will be the time (in seconds) of reverberation of a room, having all the dimensions double of those of room A ?

1

2

2

4

3

4

8

33

PYQ 2006

medium

physics ID: neet-ug-

Which one of the following statements is true ?

1

Both light and sound waves in air are transverse

2

The sound waves in air are longitudinal while the light waves are transverse

3

Both light and sound waves in air are longitudinal

4

Both light and sound waves can travel in vacuum

34

PYQ 2006

medium

physics ID: neet-ug-

Two sound waves with wavelengths 5.0 m and 5.5. m respectively, each propagate in a gas with velocity 330 m/s. We expect the following number of beats per second :-

1

6

2

12

3

0

4

1

35

PYQ 2006

medium

physics ID: neet-ug-

A transverse wave propagating along x-axis is represented by where x is in metres and t is in seconds. The speed of the wave is :-

1

2

3

4

36

PYQ 2006

medium

physics ID: neet-ug-

Two vibrating tuning forks produce waves given and Number of beats produced per minute is

1

360

2

180

3

60

4

3

37

PYQ 2008

medium

physics ID: neet-ug-

A point performs simple harmonic oscillation of period T and the equation of motion is given by After the elapse of what fraction of the time period the velocity of the point will be equal to half of its maximum velocity?

1

T/3

2

T/12

3

T/8

4

T/6

38

PYQ 2008

easy

physics ID: neet-ug-

Two periodic waves of intensities and pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is

1

2

3

4

39

PYQ 2009

medium

physics ID: neet-ug-

A wave in a string has an amplitude of . The wave travels in the +ve direction of -axis with a speed of and it is noted that 5 complete waves fit in length of the string. The equation describing the wave is

1

y = (0.02) m sin (15.7 x -2010t)

2

y = (0.02) m sin (15.7 x+ 2010t)

3

y= (0.02) m sin (7.85 x- 1005t)

4

y= (0.02) m sin (7.85 x + 1005t)

40

PYQ 2009

medium

physics ID: neet-ug-

Each of the two strings of length and are tensioned separately by force. Mass per unit length of both the strings is same and equal to . When both the strings vibrate simultaneously the number of beats is :

1

7

2

8

3

3

4

5

41

PYQ 2010

medium

physics ID: neet-ug-

A tuning fork of frequency makes beats per second with the vibrating string of a piano. The beat frequency decreases to beats per sec when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was

1

510 Hz

2

514 Hz

3

516 Hz

4

508 Hz

42

PYQ 2011

medium

physics ID: neet-ug-

Two waves are represented by the equations and where is in meter and in sec. The phase difference between them is

1

1.0 radian

2

1.25 radian

3

1.57 radian

4

0.57 radian

43

PYQ 2012

medium

physics ID: neet-ug-

A train moving at a speed of towards a stationary object, emits a sound of frequency . Some of the sound reaching the object gets reflected back to the train as echo. The frequency of the echo as detected by the driver of the train is (Speed of sound in air is)

1

3500 Hz

2

4000 Hz

3

5000 Hz

4

3000 Hz

44

PYQ 2012

easy

physics ID: neet-ug-

The equation of a simple harmonic wave is given by where and are in metres and is in seconds. The ratio of maximum particle velocity to the wave velocity is

1

2

3

4

45

PYQ 2013

medium

physics ID: neet-ug-

A wave travelling in the +ve x-direction having displacement along y-direction as 1 m, wavelength 2π in and frequency of Hz is represented by

1

y = sin(x-2t)

2

y= sin(2πx-2πt)

3

y = sin(10πx - 20πt)

4

y= sin(2πx + 2πt)

46

PYQ 2013

medium

physics ID: neet-ug-

If we study the vibration of a pipe open at both ends, then the following statement is not true

1

Open end will be anti-node

2

Odd harmonics of the fundamental frequency will be generated

3

All harmonics of the fundamental frequency will be generated

4

Pressure change will be maximum at both ends

47

PYQ 2013

easy

physics ID: neet-ug-

A wave travelling in the having displacement along -direction as, wavelength and frequency of is represented by :

1

2

3

4

48

PYQ 2014

medium

physics ID: neet-ug-

If n 1, n 2 and n 3 are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency n of the string is given by:

1

2

3

n=n 1 +n 2 +n 3

4

49

PYQ 2014

medium

physics ID: neet-ug-

The number of possible natural oscillations of air column in a pipe closed at one end of length 85 cm whose frequencies lie below 1250Hz are: (velocity of sound = 340 ms -1)

1

5

2

7

3

6

4

4

50

PYQ 2014

medium

physics ID: neet-ug-

A beam of light of \lambda = 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between first dark fringes on either side of the central bright fringe is:

1

1.2mm

2

2.4cm

3

2.4mm

4

1.2cm

51

PYQ 2015

easy

physics ID: neet-ug-

4.0 g of a gas occupies 22.4 litres at NTP. The specific heat capacity of the gas at constant volume is 5.0 . If the speed of sound in this gas at NTP is 952, then the heat capacity at constant pressure is (Take gas constant R = 8.3)

1

2

3

4

52

PYQ 2015

medium

physics ID: neet-ug-

The fundamental frequency of a closed organ pipe of length is equal to the second overtone of an organ pipe open at both the ends. The length of organ pipe open at both the ends is

1

120 cm

2

140 cm

3

80 cm

4

100 cm

53

PYQ 2016

medium

physics ID: neet-ug-

Three sound waves of equal amplitudes have frequencies . They superimpose to give beats. The number of beats produced per second will be

1

1

2

4

3

3

4

2

54

PYQ 2016

medium

physics ID: neet-ug-

The second overtone of an open organ pipe has the same frequency as the first overtone of a closed pipe metre long. The length of the open pipe will be

1

2

3

4

55

PYQ 2016

medium

physics ID: neet-ug-

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is . The next larger length of the column resonating with the same tuning fork is :

1

100 cm

2

150 cm

3

200 cm

4

66.7 cm

56

PYQ 2016

medium

physics ID: neet-ug-

A siren emitting a sound of frequency moves away from an observer towards a cliff at a speed of . Then, the frequency of sound that the observer hears in the echo reflected from the cliff is : (Take velocity of sound in air =)

1

800 Hz

2

838 Hz

3

885 Hz

4

765 Hz

57

PYQ 2017

medium

physics ID: neet-ug-

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 the system?

1

10 Hz

2

20 Hz

3

30 Hz

4

40 Hz

58

PYQ 2017

easy

physics ID: neet-ug-

Two cars moving in opposite directions approach each other with speed of and respectively. The driver of the first car blows a horn having a frequency . The frequency heard by the driver of the second car is [velocity of sound] :

1

361 Hz

2

411 Hz

3

448 Hz

4

350 Hz

59

PYQ 2017

medium

physics ID: neet-ug-

The two nearest harmonics of a tube closed at one end and open at other end are and . What is the fundamental frequency of the system ?

1

20 Hz

2

30 Hz

3

40 Hz

4

10 Hz

60

PYQ 2018

medium

physics ID: neet-ug-

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, the length of the open organ pipe is

1

16 cm

2

13.3 cm

3

12.5 cm

4

8 cm

61

PYQ 2018

medium

physics ID: neet-ug-

An em wave is propagating in a medium with a velocity . The instantaneous oscillating electric field of this em wave is along +y axis. Then the direction of oscillating magnetic field of the em wave will be along

1

- z direction

2

- y direction

3

+ z direction

4

- x direction

62

PYQ 2018

hard

physics ID: neet-ug-

A tuning fork is used to produce resonance in glass tube. The length of the air column in the tube can be adjusted by a variable piston, A room temperature of two successive resonances are produced at and column length. If the frequency of the tuning for is, the velocity of sound in air at

1

300 m/s

2

330 m/s

3

350 m/s

4

339 m/s

63

PYQ 2019

easy

physics ID: neet-ug-

A tuning fork with frequency produces resonance in a resonance column tube with upper end open and lower end closed by water surface. Successive resonance are observed at length, and . The speed of sound in air is :

64

PYQ 2020

medium

physics ID: neet-ug-

In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency . When tension in B is slightly decreased, the be at frequency increases to . If the frequency of A is, the original frequency of B will be :

1

523 Hz

2

524 Hz

3

536 H z

4

537 H z

65

PYQ 2023

medium

physics ID: neet-ug-

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:

1

1:1

2

\sqrt2:1

3

1:\sqrt2

4

1:2

66

PYQ 2023

medium

physics ID: neet-ug-

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

1

3:1

2

1:2

3

2:1

4

1:3

67

PYQ 2024

medium

physics ID: neet-ug-

The displacement of a travelling wave, where is time, is distance and is the wavelength, all in S.I. units. Then the frequency of

1

2

3

4