• Skip to main content
  • Skip to secondary menu
  • Skip to primary sidebar
  • Skip to footer

CBSE Tuts

CBSE Maths notes, CBSE physics notes, CBSE chemistry notes

  • NCERT Solutions
    • NCERT Solutions for Class 12 English Flamingo and Vistas
    • NCERT Solutions for Class 11 English
    • NCERT Solutions for Class 11 Hindi
    • NCERT Solutions for Class 12 Hindi
    • NCERT Books Free Download
  • TS Grewal
    • TS Grewal Class 12 Accountancy Solutions
    • TS Grewal Class 11 Accountancy Solutions
  • CBSE Sample Papers
  • NCERT Exemplar Problems
  • English Grammar
    • Wordfeud Cheat
  • MCQ Questions

Waves Class 11 Chapter 15 Questions And Answers

Contents

NCERT Solutions for Class 11 Physics Physics Chapter 15 Waves includes all the important topics with detailed explanation that aims to help students to understand the concepts better. Students who are preparing for their Class 11 Physics exams must go through NCERT Solutions for Class 11 Physics Physics Chapter 15 Waves. Going through the solutions provided on this page will help you to know how to approach and solve the problems.

Students can also find NCERT intext, exercises and back of chapter questions. Also working on Class 11 Physics Physics Chapter 15 Waves NCERT Solutions will be most helpful to the students to solve their Homeworks and Assignments on time. Students can also download NCERT Solutions for Class 11 Physics Physics Chapter 15 Waves PDF to access them even in offline mode.

Class 11 Physics Chapter 15 Waves NCERT Solutions

Waves NCERT Solutions

NCERT Solutions for Class 11 Physics Physics Chapter 15 Waves are been solved by expert teachers of CBSETuts.com. All the solutions given in this page are solved based on CBSE Syllabus and NCERT guidelines.

NCERT Exercises

Question 1.
A string of mass 2.50 kg is under a tension of 200 N. The length of the stretched string is 20.0m. If the transverse jerk is struck at one end of the string, how long does the disturbance take to reach the other end?
Answer:
Here, M = 2.50 kg, T = 200 N, length of the string, 1 = 20 m
Therefore, mass per unit length of the string,
NCERT Solutions for Class 11 Physics Chapter 15 Waves 1

Question 2.
A stone dropped from the top of a tower of height 300 m splashes into the water of a pond near the base of the tower. When is the splash heard at the top? Given that the speed of sound in air is 340 m s_1?
(g = 9.8 m s-2)
Answer:
Here, h = 300 m, g = 9.8 m s -2, v = 340 m s-1 if h = time taken by stone to strike the surface of water in the pond, then from
NCERT Solutions for Class 11 Physics Chapter 15 Waves 2

Question 3.
A steel wire has a length of 12.0 m and a mass of 2.10 kg. What should be the tension in the wire so that speed of a transverse wave on the wire equals to the speed of sound in dry air at 20 °C = 343 m s_1.
Answer:
Here, l = 12.0 m, M = 2.10 kg, T = ?, ν = 343 m s-1
Mass per unit length ,μ
NCERT Solutions for Class 11 Physics Chapter 15 Waves 3

Question 4.
Use the formula  \(v=\sqrt { \cfrac { \Upsilon \rho }{ \rho } } \) to explain why the speed of sound in air
(a) is independent of pressure,
(b) increases with temperature,
(c) increases with humidity.
Answer:
(a) According to Boyle’s law, we know that
PV = constant at a constant temperature … (i)
Now volume of gas, \(v=\cfrac { M }{ \rho }\)
∴ From (i) and (ii), we get
\(v=\cfrac {PM }{ \rho }\) = constant.
Since mass of a gas remains constant.
\(v=\cfrac { p }{ \rho }\) = constant.
g is always constant for a given gas or air
∴  from \(v=\sqrt { \cfrac { \Upsilon \rho }{ \rho } }\) equation ,we conclude that velocity of sound in air always remaun constant if its temperature is constant.
NCERT Solutions for Class 11 Physics Chapter 15 Waves 4
where M = ρV = molecular weight of the  gas
As ϒ,R and M are Constants, So α√T
i.e. velocity of sound in a gas is directly proportional to the square root of its I      temperature, hence we conclude that the velocity of sound in air increases with increase in temperature.
(c) Effect of humidity : The presence of water vapours in  air changes  the  density of air, thus the velocity of sound changes  with  humidity of air.
Let ρm = density of moist air.
ρd = density of dry air.
υm = velocity of sound in moist air.
υd = velocity of sound in dry air.
NCERT Solutions for Class 11 Physics Chapter 15 Waves 5
Also we know that density of water vapours is less than the density of dry air i.e. dry air is heavier than water vapours as the molecular mass of water is less than that of N2 (28) and O2 (32), so pm <  ρd.
NCERT Solutions for Class 11 Physics Chapter 15 Waves 6
i.e. velocity of sound in air increases with humidity, i.e. velocity of sound in moist air is greater than velocity of sound in dry air. That is why sound travels faster on rainy day than on a dry day.

Question 5.
You have learnt that a travelling wave in one dimension is represented by a function y = f (x, t) where x and t must appear in the combination (x – vt) to (x + vt), i.e. y = f (x ± vt). Is the converse true? Examine if the following functions for y can possibly represent a travelling wave:
(a) (x-vt)2
(b) log [(x + vt)/x0]
(c) 1/(x + vt)
Answer:
No, the converse is not true.
The basic requirement for a wave function to represent a travelling wave is that for all values of x and t, the wave function must have a finite value.
Out of the given functions for y, none of these satisfies this condition, so these functions do not represent a travelling wave.

Question 6.
A bat emits ultrasonic sound of frequency 1000 kHz in air. If this sound meets a water surface, what is the wavelength of
(a) the reflected sound,
(b) the transmitted sound? Speed of sound in air is 340 m s-1 and in water 1486 ms-1.
Answer:
Here, υ = 1000 kHz = 1000 x 103 Hz = 106 Hz;
speed of sound in air,υa = 340 m s_1;
speed of sound in water, vw = 1,486 m s_1
(a) The reflected sound: After reflection, the ultrasonic sound continues to travel in air. If λa is wavelength in air, then
NCERT Solutions for Class 11 Physics Chapter 15 Waves 7
(b) The transmitted sound : The transmitted ultrasonic sound travels in water. If λw is wavelength of ultrasonic sound in water, then
NCERT Solutions for Class 11 Physics Chapter 15 Waves 8

Question 7.
A hospital uses an ultrasonic scanner to locate tumours in a tissue. What is the wavelength of sound in the tissue in which the speed of sound is 1.7 km s1? The operating frequency of the scanner is 4.2 MHz.
Answer:
Here, υ= 1.7 km s_1 = 1.7 x 103 m s_1;
υ= 4.2 MHz = 4.2 x 106 Hz
NCERT Solutions for Class 11 Physics Chapter 15 Waves 9

Question 8.
A transverse harmonic wave on a string is described by
y(x, t) = 3.0 Sin (36 t + 0.018 x + π/4)
where x and y are in cm and t in s. The positive direction of x is from left to right.
(a)  Is this a travelling wave or a stationary wave? If it is travelling, what are the speed and direction of its propagation?
(b) What are its amplitude and frequency?
(c) What is the initial phase at the origin?
(d) What is the least distance between two successive crests in the wave?
Answer:
The equation of the form
NCERT Solutions for Class 11 Physics Chapter 15 Waves 10
represents a harmonic wave of amplitude A, wavelength l and travelling from right to left with a
velocity v.
Now, the given equation for the transverse harmonic wave is
NCERT Solutions for Class 11 Physics Chapter 15 Waves 11
(a) Since the equation (i) and (ii) are of the same form, the given equation also represents a travelling wave propagating from right to left. Further, the coefficient of t gives the speed of the wave. Therefore, v = 2000 cm s_1 = 20 m s-1
(b) Obviously, amplitude, A = 3.0 cm
NCERT Solutions for Class 11 Physics Chapter 15 Waves 12
(c) Initial phase at the origin, φ=\(\cfrac { \Pi }{ 4 }\) rad
(d) Least distance between two successive crests in the wave is equal to wavelength.
NCERT Solutions for Class 11 Physics Chapter 15 Waves 14

Question 9.
For the wave described in question no. 8, plot the displacement (y) versus (t) graphs for x = 0,2 and 4 cm. What are the shapes of these graphs? In which aspects does the oscillatory motion in travelling wave differ from one point to another: amplitude, frequency or phase?
Answer:
NCERT Solutions for Class 11 Physics Chapter 15 Waves 15

For different values of t, we calculate y using equation (i). These values are tabulated below : On plotting y versus t graph, we obtain a sinusoidal curve as shown in above figure.
NCERT Solutions for Class 11 Physics Chapter 15 Waves 16
Similar graphs are obtained for x = 2 cm and x = 4 cm.
The oscillatory motion in travelling wave differs from one point to another only in terms of phase. Amplitude and frequency of oscillatory motion remain the same in all the three cases.

Question 10.
For the travelling harmonic wave
y(x, t) = 2.0 cos 2π (10t – 0.0080 x + 0.35) Where x and y are in cm and t in s. Calculate the phase difference between oscillatory motion of two points separated by a distance of
(a) 4 m
(b) 0.5 m
(c) λ/2
(d) 3λ/4
Answer:
Given equation of a travelling harmonic wave is
y(x, t) = 2.0 cos 2π (10t – 0.0080x + 0.35) …….(i)
The standard equation of a travelling harmonic wave
NCERT Solutions for Class 11 Physics Chapter 15 Waves 17
Comparing equation (i) and (ii), we get
NCERT Solutions for Class 11 Physics Chapter 15 Waves 18
Question 11.
The transverse displacement of a string (clamped at its two ends) is given by
y(x,f) = 0.06sin\((\cfrac { 2\Pi }{ 3 } x)\) cos(120 πt)
Where x and y are in m and t in s. The length of the string is 1.5 m and its mass is 3.0 x 10 2 kg. Answer the following:
(a) Does the function represent a travelling wave or a stationary wave?
(b) Interpret the wave as a superposition of two waves travelling in opposite directions. What are the wavelength, frequency, and speed of each wave?
(c) Determine the tension in the string.
Answer:
Here, the equation for transverse displacement is given by
y(x,f) = 0.06sin\( \cfrac { 2\Pi }{ 3 } x \) cos 120 πt …………(i)
(a) The displacement, which involves harmonic functions of x and f separately, represents a stationary wave and the displacement, which is harmonic function of the form (υt ± x), represents a travelling wave. Hence, the equation given above represents a stationary wave.
(b) When a wave pulse
NCERT Solutions for Class 11 Physics Chapter 15 Waves 19
Question 12.
(i) For the wave on a string described in question no. 11, do all the points on the string oscillate with the same
(a) frequency,
(b) phase,
(c) amplitude? Explain your answers.
(ii) What is the amplitude of a point 0.375 m away from one end?
Answer:
(i) All the points on the string
(a) have the same frequency of oscillation (except at the nodes, where the frequency is zero).
(b) have the same phase between two adjacent nodes,
(c) but not the same amplitude.
(ii) Now, the amplitude of the given wave is
A = 0.06 sin \( \cfrac { 2\Pi }{ 3 } x \)
At x = 0.375 m, the amplitude is given by
A(at x = 0.375 m) = 0.06 sin \( \cfrac { 2\Pi }{ 3 } x \) x 0.375
= 0 06 sin \(\frac { \Pi }{ 4 }\) = 0.06 x 0.707 = 0.042 m 4

Question 13.
Given below are some functions of x and t to represent the displacement (transverse or longitudinal) of an elastic wave. State which of these represent
(1) a travelling wave,
(2) a stationary wave or
(3) none at all:

(a) y=2cos(3x)sin(10t)
(b) y = 2-√x-vt
(c) y = 3 sin (5x – 0.5 t) + 4 cos (5x – 0.5t)
(d) y = cos x sin t + cos 2x sin 2t

Answer:
(a) This equation has two harmonic functions of each x and t separately, so it represents stationary wave.
(b) This function does not represent any wave as it contains no harmonic function.
(c) It represents progressive/travelling harmonic wave as the arguments of cosine and sin functions are same.
(d) This equation is the sum of two functions cos x sin t and cos 2x sin 2t each represen­ting a stationary wave. Therefore it represents superposition of two stationary waves

Question 14.
A wire stretched between two rigid supports vibrates in its fundamental mode with a frequency of 45 Hz. The mass of the wire is 3.5 x 10-2 kg and its linear mass density is 4.0 x 10 2 kg m-1. What is
(a) the speed of a transverse wave on the string, and
(b) the tension in the string?
Answer:
Here, υ = 45 Hz, M = 3.5 x 10-2 kg;
mass/length =μ = 4.0 x  10-2  kg m-1
NCERT Solutions for Class 11 Physics Chapter 15 Waves 20
Question 15.
A meter-long tube open at one end, with a movable piston at the other end, shows resonance with a fixed frequency source (a tuning fork of frequency 340 Hz) when the tube length is 25.5 cm or 79.3 cm. Estimate the speed of sound in air at the temperature of the experiment. The edge effects may be neglected.
Answer:
As there is a piston at one end of the tube, it behaves as a closed organ pipe, which produces odd harmonics only. Therefore, the pipe is in resonance with the fundamental note and the third harmonic (79.3 cm is about 3 times 25.5 cm]
In the fundamental mode, \(\frac { \Pi }{ 4 }\) = l1= 25.5 cm
λ = 4 x 25.5 = 102 cm = 1.02 m.
Speed of sound in air,
υ = υλ= 340 x 1.02 = 346.8 m s-1.

Question 16.
A steel rod 100 cm long is clamped at its middle. The fundamental frequency of longitudinal vibrations of the rod are given to be 2.53 kHz. What is speed of sound in steel?
Answer:
NCERT Solutions for Class 11 Physics Chapter 15 Waves 21

A rod clamped in the middle has antinodes (A) at its ends and node (N) at the point of clamping. In fundamental mode, thus the length of the rod is
l=\(\frac { \Pi }{ 2 }\) or 2l
Where l = length of rod and also λ = wavelength of the wave
Here, l = 100 cm
υ = 2.53 kHz = 2.53 x 10 3 Hz
∴ λ= 2 x 100 = 200 cm
If υ be the speed of sound in steel, then
υ = υ λ = 2.53 x 103 x 200
= 506 x 103 cm s_1
= 5.06 x 103 ms-1
υ= 5.06 km s_1.

Question 17.
A pipe 20 cm long is closed at one end. Which harmonic mode of the pipe is resonantly excited by a 430 Hz source? Will the same source be in resonance with the pipe if both ends are open? (speed of sound in air is 340 m s_1
Answer:
Here, L = 20 cm = 0.2 m, υ„ = 430 Hz, υ= 340 m s_1
The frequency of nth normal mode of vibration of closed pipe is
NCERT Solutions for Class 11 Physics Chapter 15 Waves 22
NCERT Solutions for Class 11 Physics Chapter 15 Waves 23
Question 18.
Two sitar strings A and B playing the note ‘Ga’ are slight out of tune and produce beats of frequency 6 Hz. The tension in the string A is slightly reduced and the beat frequency is found to reduce to 3 Hz. If the original frequency of A is 324 Hz, what is the frequency of B?
Answer:
We know that  υ ∝ √T
where u = frequency, T = tension
The decrease in the tension of a string decreases its frequency.
So let us assume that original frequency υA of A is more than the frequency υB of B.
Thus υA – υB = ± 6 Hz (given)
and υA = 324 Hz
∴  324 – υB  = ± 6
or υB = 324 ± 6 = 318 Hz or 330 Hz.
On reducing tension of A, Δυ= 3 Hz
If υB  = 330 Hz and on decreasing tension in A, will be reduced i.e. no. of beats will increase, but this is not so because no. of beats becomes 3.
∴ must be 318 Hz because on reducing the tension in string A, its frequency may be reduced to 321 Hz, thus giving 3 beats with υB = 318 Hz.

Question 19.
Explain why (or how):
(a) in a sound wave, a displacement node is a pressure antinode and vice versa,
(b) bats can ascertain distances, directions, nature and sizes of the obstacles without any “eyes”,
(c) a violin note and sitar note may have the same frequency, yet we can distinguish between the two notes,
(d) solids can support both longitudinal and transverse waves, but only longitudinal waves can propagate in gases, and
(e) the shape of a pulse gets distorted during propagation in a dispersive medium.
Answer:
(a) In a sound wave, a node is a point where the amplitude of oscillation i.e. displacement is zero as here a compression and a rarefaction meet and the pressure is maximum, so it is called pressure antinode. While an antinode is a point where the amplitude of oscillation is maximum i.e. displacement is maximum but pressure is minimum. So this point is called pressure node.
Hence displacement node coincides with pressure antinode and displacement antinode with pressure node.
(b) Bats emit ultrasonic waves of large frequencies (small wavelength) when they fly. These ultrasonic waves are received by them after reflection from the obstacle. Their ears are so sensitive and trained that they not only get the information of the distance of the obstacle but also that of the nature of the reflecting surface.
(c) The quality of the sound produced by an instrument depends upon the number of overtones. Since the number of overtones is different in the cases of sounds produced by violin and sitar therefore we can distinguish through them.
(d) Solids possess both the volume elasticity and the shear elasticity. Therefore they can support both longitudinal and transverse waves.
On the other hand, gases have only the volume elasticity and no shear elasticity, so only longitudinal waves can propagate in gases.
(e) A sound pulse is a combination of waves of different wavelengths. In a dispersive medium, the waves of different wavelengths travel with different speeds in different directions e. with different velocities. So the shape of the pulse gets distorted i.e. a plane wave front in a non- dispersive medium does not remain a plane wave front in a dispersive medium.

Question 20.
A train, standing at the outer signal of a railway station blows a whistle of frequency 400 Hz in still air.
(i) What is the frequency of the whistle for a platform observer when the train
(a) approaches the platform with a speed of 10 m s-1.
(b) recedes from the platform with a speed of 10 m s-1?
(ii) What is the speed of sound in each case? The speed of sound in still air can be taken as 340 ms1.
Answer:
Here, frequency of source of sound,υ = 400 Hz; v = 340 m s_1 = speed of sound
Speed of source = υs = 10m s_1
(i) (a) When the train approaches the platform, the apparent frequency as heard by the observer on the platform will be
NCERT Solutions for Class 11 Physics Chapter 15 Waves 24
(b) When the train recedes from the platform, the apparent frequency as heard by the observer is given by according to the formula :
NCERT Solutions for Class 11 Physics Chapter 15 Waves 25
(ii) The speed of sound in each case remains same i.e.340 ms-1.

Question 21.
A train, standing in a station-yard, blows a whistle of frequency 400 Hz in still air. The wind starts blowing in the direction from the yard to the station with a speed of 10 m s-1. What are the frequency, wavelength, and speed of sound for an observer standing on the station platform? Is the situation exactly identical to the case when the air is still and the observer runs towards the yard at a speed of 10 m s-1? The speed of sound in still air can be taken as 340 m s-1.
Answer:
Here, v = 340 m s-1; υ = 400 Hz
(a) Speed of the wind, vw = 10 m s-1
As the direction of blow of wind (yard to station) is the same as the direction of sound, therefore, for the observer standing on the platform; velocity of sound,
υ’ =υ + υw = 340 + 10 = 350 m s-1
As there is no relative motion between source of the sound and the observer, the frequency of sound will remain unchanged.
Thus, frequency of sound = 400 Hz
Wavelength of sound,
NCERT Solutions for Class 11 Physics Chapter 15 Waves 26
(b) Speed of the observer, υ0 = 10 m s-1 (towards yard). When the observer moves towards the source of sound, the apparent frequency,
NCERT Solutions for Class 11 Physics Chapter 15 Waves 27
The wavelength of sound waves is not affected due to the motion of the observer and hence the wavelength of the sound waves will remain unchanged.
Speed of sound relative to the observer
= 340 + 10 = 350 m s-1
Therefore, situations (a) and (b) are not equivalent.

Question 22.
A travelling harmonic wave on a string is described by y (x, t) = 7.5 sin (0.0050 + 12t + π/4)
(a) What are the displacement and velocity of oscillation of a point at x = 1 cm, and t = 1 s? Is this velocity equal to the velocity of wave propagation?
(b) Locate the points of the string which have the same transverse displacement and velocity as the x = 1 cm point at f = 2 s, 5 s and 11s.
Answer:
NCERT Solutions for Class 11 Physics Chapter 15 Waves 28

NCERT Solutions for Class 11 Physics Chapter 15 Waves 29
NCERT Solutions for Class 11 Physics Chapter 15 Waves 30
Question 23.
A narrow sound pulse (for example, a short pip by a whistle) is sent across a medium.
Does the pulse have a definite (i) frequency, (ii) wavelength, (iii) speed of propagation?
If the pulse rate is 1 after every 20 s, that is the whistle is blown for a split of second after every 20 s, is the frequency of the note produced by the whistle equal to 1/20 or 0.05 Hz?
Answer:
(a) A narrow sound pulse such as a short pip by a whistle does not have a definite wavelength or frequency. However, being a sound wave, it has a definite speed.
(b) If a short pip is produced after every 20 s, then frequency of the note produced by the whistle cannot be called 1/20 or 0.05 Hz. We may call 0.05 Hz as the frequency of repetition of the short pip.

Question 24.
One end of a long string of linear mass density 8 x 10 3 kg m-1 is connected to an electrically driven tuning fork of frequency 256 Hz. The other end passes over a pulley and is tied to a pan containing a mass of 90 kg. The pulley end absorbs all the incoming energy so that reflected waves at this end have negligible amplitude. At t=0, the left end (fork end) of the string x = 0 has zero transverse displacement (y = 0) and is moving along positive y-direction. The amplitude of the wave is 5.0 cm. Write down the transverse displacement y as function of x and t that describes the wave on the string.
Answer:
Here, μ = 8.0 x 10-3 kg m-1, u = 256 Hz,
T= 90 kg = 90 x 9.8 = 882 N
Amplitude of wave, A =0 cm = 0.05 m.
As, the wave propagating along the string is a transverse travelling wave, the velocity of the wave is given by
NCERT Solutions for Class 11 Physics Chapter 15 Waves 31
As, the wave is propagating along positive x direction the equation of the wave is
y(x-t) =A sin(ωt-kx)
= 0.05 sin (1.61 x 103 t- 4.84 x)
Here x, y, are in meter and t is in second.

Question 25.
A SONAR system fixed in a submarine operator at a frequency 40.0 kHz. An enemy submarine moves towards the SONAR with a speed of 360 km h-1. What is the frequency of sound reflected by the submarine? Take the speed of sound in water to be 1450 m s-1.
Answer:
Here, μ = 40.0 kHz ;
Speed of sound wave in water, υ = 1, 450 m s_1
The frequency of the waves from SONAR system will undergo a change in the following two steps:
(1) Frequency of waves from SONAR system as received by the enemy submarine moving towards the system :
NCERT Solutions for Class 11 Physics Chapter 15 Waves 32

(2) Frequency of waves from the enemy’s submarine as received by SONAR system : The enemy submarine will reflect the waves of frequency υ’ = 42.756 kHz and will thus act as a source of waves moving with a speed; υs = 100 m s_1 toward the SONAR system (listener). If υ” is the apparent frequency as received by SONAR system, then
NCERT Solutions for Class 11 Physics Chapter 15 Waves 33

Question 26.
Earthquakes generate sound waves inside the earth. Unlike a gas, the earth can experience both transverse (S) and longitudinal (P) sound waves. Typically the speed of S wave is about km s-1, and that of P wave is 8.0 km s-1. A seismograph records P and S waves from an earthquake. The first P wave arrives 4 min before the first S wave. Assuming the waves travel in straight line, at what distance does the earthquake occur?
Answer:
Let υ1,υ2 be the velocities of S waves and P waves, and t1 ,t2 be the time taken by these waves to travel to the position of seismograph. If l is the distance of occurrence of earthquake from the seismograph, then
l = υ1t1 = υ2t2       -(i)
Now, υ1= 4 km s_1 and υ2 = 8 km s_1
∴  4t1 =8 t2 or t1 = 2t2               …(ii)
Also, t1 – t2 = 4 min = 240 s.
Using (ii), 2t2 – t2 = 240 s ;t2 = 240 s
t1= 2 x t2 = 2 x 240 = 480 s
Now, from (i) l = υ1t1 = 4 x 480 = 1920 km.
Hence earthquake occurs 1920 km away from the seismograph.

Question 27.
A bat is flitting about in a cave, navigating via ultrasonic beeps. Assume that the sound emission frequency of the bat is 40 kHz. During one fast swoop directly towards a flat wall surface, the bat is moving at 0.03 times the speed of the sound in air. What frequency does the bat hear reflected off the wall?
Answer:
Here, υ = 40 kHz,
speed of sound in air,υ = 340 m s_1
∴  v’ = speed of bat
= 0.03 x υ = 0.03 x 340 = 10.20 m s-1
NCERT Solutions for Class 11 Physics Chapter 15 Waves 34
The bat moving towards wall acts as a moving source and for the sound waves reflected from the wall, it acts as a moving observer. Thus the source and observer are approaching each other with same speed. i.e. υs = υ0 = υ’ = 10.2 m s-1
Thus apparent frequency of the reflected sound waves heard by the bat is given by
NCERT Solutions for Class 11 Physics Chapter 15 Waves 35

Now that you are provided all the necessary information regarding NCERT Solutions for Class 11 Physics Physics Chapter 15 Waves and we hope this detailed NCERT Solutions are helpful.

NCERT Solutions for Class 11 Physics

Class 11 Physics NCERT Solutions

  • Physical World Class 11 NCERT Solutions
  • Units and Measurements Class 11 NCERT Solutions
  • Motion in a Straight Line Class 11 NCERT Solutions
  • Motion in a Plane Class 11 NCERT Solutions
  • Laws of Motion Class 11 NCERT Solutions
  • Work Energy and Power Class 11 NCERT Solutions
  • System of Particles and Rotational Motion Class 11 NCERT Solutions
  • Gravitation Class 11 NCERT Solutions
  • Mechanical Properties of Solids Class 11 NCERT Solutions
  • Mechanical Properties of Fluids Class 11 NCERT Solutions
  • Thermal Properties of Matter Class 11 NCERT Solutions
  • Thermodynamics Class 11 NCERT Solutions
  • Kinetic Theory Class 11 NCERT Solutions
  • Oscillations Class 11 NCERT Solutions
  • Waves Class 11 NCERT Solutions

Primary Sidebar

NCERT Exemplar problems With Solutions CBSE Previous Year Questions with Solutoins CBSE Sample Papers
  • The Summer Of The Beautiful White Horse Answers
  • Job Application Letter class 12 Samples
  • Science Lab Manual Class 9
  • Letter to The Editor Class 12 Samples
  • Unseen Passage For Class 6 Answers
  • NCERT Solutions for Class 12 Hindi Core
  • Invitation and Replies Class 12 Examples
  • Advertisement Writing Class 11 Examples
  • Lab Manual Class 10 Science

Recent Posts

  • Understanding Diversity Question Answer Class 6 Social Science Civics Chapter 1 NCERT Solutions
  • Our Changing Earth Question Answer Class 7 Social Science Geography Chapter 3 NCERT Solutions
  • Inside Our Earth Question Answer Class 7 Social Science Geography Chapter 2 NCERT Solutions
  • Rulers and Buildings Question Answer Class 7 Social Science History Chapter 5 NCERT Solutions
  • On Equality Question Answer Class 7 Social Science Civics Chapter 1 NCERT Solutions
  • Role of the Government in Health Question Answer Class 7 Social Science Civics Chapter 2 NCERT Solutions
  • Vital Villages, Thriving Towns Question Answer Class 6 Social Science History Chapter 9 NCERT Solutions
  • New Empires and Kingdoms Question Answer Class 6 Social Science History Chapter 11 NCERT Solutions
  • The Delhi Sultans Question Answer Class 7 Social Science History Chapter 3 NCERT Solutions
  • The Mughal Empire Question Answer Class 7 Social Science History Chapter 4 NCERT Solutions
  • India: Climate Vegetation and Wildlife Question Answer Class 6 Social Science Geography Chapter 8 NCERT Solutions
  • Traders, Kings and Pilgrims Question Answer Class 6 Social Science History Chapter 10 NCERT Solutions
  • Environment Question Answer Class 7 Social Science Geography Chapter 1 NCERT Solutions
  • Understanding Advertising Question Answer Class 7 Social Science Civics Chapter 7 NCERT Solutions
  • The Making of Regional Cultures Question Answer Class 7 Social Science History Chapter 9 NCERT Solutions

Footer

Maths NCERT Solutions

NCERT Solutions for Class 12 Maths
NCERT Solutions for Class 11 Maths
NCERT Solutions for Class 10 Maths
NCERT Solutions for Class 9 Maths
NCERT Solutions for Class 8 Maths
NCERT Solutions for Class 7 Maths
NCERT Solutions for Class 6 Maths

SCIENCE NCERT SOLUTIONS

NCERT Solutions for Class 12 Physics
NCERT Solutions for Class 12 Chemistry
NCERT Solutions for Class 11 Physics
NCERT Solutions for Class 11 Chemistry
NCERT Solutions for Class 10 Science
NCERT Solutions for Class 9 Science
NCERT Solutions for Class 7 Science
MCQ Questions NCERT Solutions
CBSE Sample Papers
NCERT Exemplar Solutions LCM and GCF Calculator
TS Grewal Accountancy Class 12 Solutions
TS Grewal Accountancy Class 11 Solutions