Sound Waves Questions and Answers

th The frequency of whistle of an engine appears to be of initial frequency when it crosses a stationary observer If the velocity of sound is 330 m s the speed of engine is given by 330 n then

A 20 cm long string having a mass of 1 0 g is fixed at both the ends The tension in the string is 0 5 N The string is set into vibration using an external vibrator of frequency 100 Hz Find the separation in cm between the successive nodes on the string

16 The fundamental frequency of a pipe closed at one end is 100 Hz If close end is open the fundamental frequency of same pipe will be 1 100 Hz 2 200 Hz 4 400 Hz 3 50 Hz 17 Two tuning fork A and B are sounded together gives 5 beats per second If frequency of B is 260 Hz and after loading B with wax the beat frequency increases the frequency of A is

in solids 22 Longitudinal waves of wavelength 2 propagate in a gaseous medium in the form of compressions and rarefactions The distance between two adjacent compression is 1 2 2 32 4 23 The simple harmonis 2 2 1 24 12 3

Let speed of sound waves in hydrogen gas at 30 room temperature is vo What will be the speed of sound waves in a room which contains an equimolar mixture of hydrogen and He at same temperature e 2 MIT HIS N 2 Vo vo A B C F 1 2 2 575 55 2 a Vo af

3 825 m 4 660 m A B and C are three tuning forks the frequency of 10 A is 350 Hz A and B produce 5 beats sec While B and C produce 4 beats sec When A is loaded with wax it produces 2 beats s with B and 6 beats s with C The frequency of B C is 1 341 Hz 359 Hz 2 345 Hz 341 Hz 3 359 Hz 345 Hz 4 355 Hz 341 Hz 3 825 m 4 660 m ABC A350 Hz A B atas fazia tasc4 faria s A A A E B 2 6f Bac fai RIT 1 341 Hz 359 Hz 2 345 Hz 341 Hz 3 359 Hz 345 Hz 4 355 Hz 341 Hz

A bus B is moving with a velocity V in the positive x direction along a road as shown in the figure A shooter S is at a distance I from the road He has a detector which can detect signals only of frequency 1500 Hz The bus blows horn of frequency 1000 Hz When the detector detects a signal the shooter immediately shoots towards the road along SC and the bullet hits the bus The velocity of bullet in m s neglect the effect of g the acceleration due to gravity if velocity of sound in air is V 340 m s and V B 2 3 3 V C Road X Am 136

A toy car blowing its horn is moving with a steady speed of 5 m s away from a wall An observer towards whom the toy car is moving is able to hear 5 beats per second If the velocity of sound in air is 340 m s the frequency of the horn of the toy car is close to 1 340 Hz 2 510 Hz 3 170 Hz 4 680 Hz

When a source of sound of frequency 600 Hz moves with velocity 30 m s towards a stationary observer the apparent wavelength is If the same source is kept stationary and the observer is moved with same velocity 30 m s towards the source then apparent wavelength is X then find A in cm for speed of sound in air to be 340 m s estion Type Numerical Type

Physics Question Palette Question No 22 A glass tube of length 0 5 m is filled with water and can be drained out slowly at the bottom of the tube If a vibrating tuning fork of frequency 500 Hz is brought at the upper end of the tube the number of resonance obtained will be Speed of sound 330 m s

5 When two waves with same frequency and constant phase difference interfere 1 There is gain of energy 2 There is a loss of energy 3 The energy is redistributed and distribution remains constant in time 4 The energy is redistributed and distribution changes with time

upper A tuning fork with frequency 800 Hz produces resonance in a resonance column tube with end open and lower end closed by water surface Successive resonance are observed at length 9 75 cm 31 25 cm and 52 75 cm The speed of sound in air is 1 500 m s 2 156 m s 3 344 m s 4 172 m s

A small source of sound is in uniform circular motion of radius R and angular speed 7 10 rad s It emits continuous sound of fixed frequency fo A detector placed at a distance 2R from the centre and in the plane of the circle records frequencies with maximum value 1200 Hz and minimum value 800 Hz Take the speed of sound to be 330 m s Select the correct statement s R 240 m fo 960 Hz The distance of the source from the detector when it emits the signal which is detected to be 800 Hz is 210 m The speed of source is 66 m s 1

A military band was marching on a street in the same direction as the normal traffic flow A motorist was approching the band from behind in his car just at the moment when they were playing the musical note A frequency 440Hz in unison The same band performance was also simultaneously being broad live on the ratio from a stationary microphone which was situated on the sidewalk just ahead of the band The motorist noticed that the combination of the direct sound coming from the band ahead of the band brodcast produced discernible beats Timing the beats he counted 4 beats in 3seconds He noted from the speedmeter that his car was travelling at 18 kilometers per hour Calculate the speed in meters per seconds at which the band was marching assuming that the speed of sound on that day was 1 330ms It was a very cold day

A road passes at some distance from a standing man A truck is coming on the road with some acceleration The truck driver blo a whistle of frequency 500Hz when the line joining the truck and the man makes an angle with the road The man hears a not having a note having a frequency of 600Hz when the truck is closest to him Also the speed of truck has git doubled during this time Find the value of 0

When 1m long metallic wire is stressed an extension of 0 02m is produced An organ pipe 0 5m long and open at both ends whe sounded with this stressed metallic wire produced 8 beats in its fundamental mode By decreasing the stress in the wire the numb of beats are found to decrease Find the Young s modulus of the wire The density of metallic wire is 104kg m and velocity of sound in air is 292m s

In an organ pipe may be closed or open of 99cm length standing wave is set up whose equation is given by longitudinal displacement y K COS 2T 0 1mm y 1cm cos 400 twhere y is measured from the top of the tube in metres and 0 8 tin seconds Here 1cm is the end correction Equation of the standing wave in terms of excess pressure is take bulk modulus 5 x 10 N m

A stationary source is emitting sound at a fixed frequency f which is reflected by two cars approaching the source The difference between the frequencies of sound reflected from the cars is 1 2 of fo What is the difference in the speeds of the cars in km per hour to the nearest integer The cars are moving at constant speeds much smaller than the speed of sound which is 330 ms YOUR ANSWER 1 1

Two point sound sources A and B each to power 25w and frequency 850Hz are 1m apart The sources are in phase 90 M 2 4m AD a Determine the phase difference between the waves emitting from A and B received by detector D as shown in figure b Also determine the intensity of the resultant sound wave as recorded by detector D Velocity of sound

A tube open at only one end is cut into two tubes of non equal lengths The piece open at both ends has of fundamenal frequency of 450Hz and other has fundamental frequency of 675 Hz What is the 1st overtone frequency of the original tube

A sound wave of frequency 80Hz is travelling with speed 320m s a Find the change in phase at a given position in 400ms b Find the phase difference between two positions seperated by 20cm at a particular instant

A person standing on an open ground hears the sound of a jet aeroplane coming from north at an angle 60 with ground level But he finds the aeroplane right vertically above his position If v is the speed of sound speed of the plane is 1 2v 3 3

A closed on one end organ pipe has a fundamental frequency of 528 Hz at 20 C a What is the fundamental frequency when the temperature is 0 C b What are the frequencies of the first 3 overtones at 20 C

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 1 13 2 cm 2 8 cm 3 12 5 cm 4 16 cm

EX1 Calculate the attenuation of the sound s intensity of Lair 10 W m when it goes from air into water Lar water Dai 1 29 kg m Pwater 10 kg m car 330 m s Cwater 1500 m s Could this sound be heard into water 1 3

What will be the velocity of sound if the temperature of air is increased by 1 C Velocity of sound at 0 C is 332 m sec 1 330 m sec 2 360 m sec 3 337 6 m sec

a periodic 2 22 The displacement of a particle in displacement may be considered as the result given by y 4 cos t 2 sin 1000t This superposition of n independent harmonic oscillation WB JEE 20 4 Here n is a 1 b 2 c 3 The time period of a simple pendul motion

Why answer is given 43 I am getting 46 please help At 20 m from a line source the loudness of the sound is 40 dB At 10 m from the source the loudness will be 43 dB 46 dB 80 dB 37 dB Asked by 1252224 aesl id Standard XII Stream NEET Aug 1 2021 a 12 50 PM Add your responses Type Text Type your answer here OR you can upload an attachment from the option below

A train approaching a hill at a speed of 40 km hr sounds a whistle of frequency 580 Hz when it is at a distance of 1 km from hill A wind with a speed of 40 km hr is blowing in the direction of motion of the train Find the frequency of the whistle as heard by an observer on the hill Velocity of sound in air 1 200 km hr Question Type Single Correct Type 1 599 Hz 2 699 Hz 3 499 Hz 4 799 Hz

O Five beats are produced by simultaneously blowing two closed organ pipes of different lengths in their fundamental mode If the shorter organ pipe is 25 cm in length and speed of sound in air is 320 m s What is the length of other organ pipe 1 25 4 cm 3 19 6 cm 2 27 2 cm 4 32 5 cm

range ISR 1 us 100 s RINA RISK Options 1 2 3 A 15 cm 15 m 15 km 150 km

A train is moving at a constant speed of v 90 km h on a straight level track From a railway station P on the track there is a village Q at a distance y 1 2 km in a direction perpendicular to the track When the engine E is x 1 6 km away from the station the driver honks a beep of horn of duration r 44 s Calculate durations of the honking tp and to heard at the station and in the village Speed of sound in still air is c 350 m s and there is no wind P

36 A sound wave of wavelength 40 cm travels in air If the difference between the maximum and minimum pressures at a given point is 1x 10 3 N m2 What will be the amplitude of vibration of the particle of the medium the bulk modulus of air is 1 4 x 10 10 N m a 4 4x10 10 m b 3 3 10 10 m c 1 1x10 0 m d 2 2 10 m

Imagine a very thin uniform wire of length L meter and total mass 1 gram Fix one end o f the wire in the ceiling hang a large mass o f 1 kg from the other end then pluck the wir e L 4 meter from the top Assume that as th e wire vibrates the large mass is not movin g The lowest frequency heard by us is 100 Hz What is the length of the wire in motor

A source is moving a long a circle x y R with constant speed V 330 m s in clockwise direction while an observer is stationary at point 6 3 2R 0 with respect to centre of circle Frequency emitted by the source is f Velocity of sound in air is 330 m s Then choose correct option from the following A The coordinate of source when observer record maximum frequency is 3R R 2 2 B The coordinate of source when observer record minimum frequency is RR 2 C The coordinate of source when observer record minimum frequency is 0 R D The coordinate of source when observer record maximum frequency is R 3 2

Attempt All 35 questions At a place the speed of sound of frequency 400 Hz is V At the same place the speed of 200Hz sound will be 2V OV WA 3

Pressure variation due a sonic wave propagating along positive x direction is given by equation AP x AP sin 2 vt x One end of an open organ pipe is closed by a cap and held at rest with its axis parallel to x axis and the open end at the origin The minimum value of limiting frictional force in Newton between the cap and the pipe so that pipe will remain closed is Given AP 2 x 10 N m and cross sectional area of the tube is equal to 5 104 m

An observer moves away from a linear source of sound The loudness level decreases by 10 dB whe the distance of observer from source A Increases 100 times C Decreases 100 times B Increases 10 times D Decreases 10 times

A closed organ pipe is vibrating in its second overtone The length of the pipe is 10cm and maximum amplitude of vibration of particles of the air in the pipe is 2mm Then the amplitude of S H M of the particles at 9cm from the open end is A 3 mm B 2 mm C 3 2 mm D none of these

f a source of frequency f and a listener approaches each other with a velocity of of the velocity of sound each the apparent frequency heard by the listener is 20 21 20 0 19 f 21 021 4 19 20 21

A source of sound with natural frequency moves uniformly along a straight line A stationary sound detector is located at a distance of 300 m from the straight line When the source is closest to the detector it records a frequency of 3f as received from the source Find the distance in m of the source from the detector at the instant when it record natural frequency of the source If your answer is 300 where x y are reduces to nearest integers from 1 to 9 then fill value x y

25 The speed limit for vehicles on a road is 100 km hr A policeman detects a drop of 20 in the pitch of the horn of a car as it passes him Is the policeman justified in punishing the car driver for crossing the speed limit Velocity of sound in air 340 m s

View In English A car blowing a horn of frequency 350 Hz is moving normally towards a wall with a speed of 5 m s The beat frequency heard by a person standing between the car and the wall is speed of sound in air 350 m s 1 3 3 Correct Answer 1 Your Answer 3 Status incorrect Add to Bookmark list zero 3 5 Hz 5 Hz 10 Hz

at a speec tected by d in air is 330 18 towards a stationary object emits a sound of frequency 1000 Hz Some of the sound reaching the object gets reflected back to the train as acha The frequency of of the train is 5000 Hz 3000 Hz 3500 Hz 4000 Hz

1 In the diagram not to scale each of the loudspeakers 41 frager safe aff Q safa34f emits a continuous sound of the same frequency A microphone moved along the line PQ detects a series of maximum and minimum sound intensities Which one of the following actions on its own will lead to an increase in the distance between the maxima of sound intensity Loudspeaker Loudspeaker 1 Decreasing the frequency of the sound emitted by the loudspeakers 2 Increasing the frequency of the sound emitted by the loudspeakers 3 Increasing the distance of the loudspeakers 4 Decreasing the distance of the loudspeakers from the line PO en fagar Loudspeaker Loudspeaker 1 Brufuta af at ang 2 GIGS PAGRI P erant onferen 3 4 PQI

fa b c a violin note and sitar note may have the same frequency yet we can distinguish between the two notes d in a sound wave a displacement node is a pressure antinode and vice versa bats can ascertain distances directions nature and sizes of the obstacles without any eyes e solids can support both longitudinal and transverse waves but only longitudinal waves can propagate in gases and the shape of a pulse gets distorted during propagation in a dispersive medium

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 peed of 10 m s What are the frequency wavelength and speed of sound for an observer standing on the station s 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 The speed of sound in still air can be taken as 340 m s

ationary sound source The source emits a beep of sound of frequency vo 262 Hz propagates with speed c 330 m s The detector detects the beep of sound over a distance Ax 78 m and registers a frequency v 275 H Find duration of the beep emitted by the source that S sec Ano VAK C u vo

SolveLancer Test Sound pollution is dangerous to human health Sound level near an industry increased by 20dB Then find the increment in pressure amplitude SolveLancer Test a 10 b 1000 c 100 d 1 a b

Consider a situation i that two sound waves Y 0 2m sin 504 t x 300 and Y2 0 6 m sin 496 t x 300 are super imposed Consider another situation ii that two sound waves y 0 4m sin 504x t x 300 and y2 0 4 m sin 504 t x 300 are superimposed Match the following A In situation i B In situation ii Column 1 gost pr eWhen two waves of same frequency and amplitude and travelling in opposite directions superimpose 1 p q Column Il Stationary waves are formed There will be phenomenon of beats r Amplitude of the resultant wave will vary periodically with position D If the intensity of sound alternately increases and s Amplitude of the resultant decreases periodically a result of superposition of waves of highly different frequencies q t wave will vary periodically with time Frequency of vibration of the medium particle changes after superposition of two waves