Sound Waves Questions and Answers

90 71 6 18 4 3 A string 2 0 m long and fixed at its ends is driven by a 240 Hz vibrator The string vibrates in i third harmonic mode The speed of the wave and its fundamental frequency is 1 320 m s 120 Hz 2 320 m s 80 Hz 3 180 ms 80 Hz 4 180 m s 120 Hz Key 2

Two students are participating in a lab where they make waves on a long spring One student starts by making 2 waves appear on the spring then gradually moves her hand at a faster rate in order to produce 4 waves on the spring Which answer best describes what the student changed about the wave on the spring a Since there are more waves occurring in the same space the frequency of the waves has increased while the wavelength of the wave decreased Ob Since there are more waves occurring in the same space the frequency of the waves has increased while the speed of the wave decreased c Since there are more waves occurring in the same space the wavelength of the waves has increased while the frequency of the wave decreased d Since there are more waves occurring in the same space the wavelength of the waves has increased while the speed of the wave decreased

F 74 A person P is 600 m away from the station when train is approaching station with 72 km h it blows a whistle of frequency 800 Hz when 800 m away from the station Find the frequency heard by the person Speed of sound 340 ms a 800 Hz c 829 5 Hz 800 m b 839 5 Hz d 843 5 Hz S 600 m P

33 34 35 1 2 A person B accidentally slips from a large building and screams with a sound of constant frequency n as he falls as shown in the figure The apparent frequency of the sound of the scream as heard by the person A at the top of the building is dependent on time as v is speed of sound n n B 36 Question Type Single Correct Type 3 n n V v gt V n n gt 37 38 39 40 41 2v 2x at EEEE 000 4

23 A string of length L is stretched by L 20 and speed of transverse wave along it is v The speed of wave when it is stretched by L 10 will be assume that Hooke s law is applicable a 2v c 2v b d 4v

A bus is moving towards a huge wall with a velocity of 5 m s The driver sounds a horn of frequency 200 Hz The frequency of the beats heard by a passenger of the bus will be In Hz nearly velocity of sound in air 338 m s

In a long cylindrical tube an air column is constructed by fitting a movable piston A tuning fork of frequency 416Hz sends longitudinal sound waves Consider the speed of sound in the air as 333m s It is observed that the air column in the tube vibrates in its fundamental frequency How far from the open end should the piston be in this situation A 10cm B 20cm c 30cm D 40cm

24 An organ pipe closed at one end has fundamental frequency of 1500 Hz The maximum number of overtones generated by this pipe which a normal person can hear is AIIMS 2004 1 14 2 13 3 6 4 9

A person B accidentally slips from a large building and screams with a sound of constant frequency n as he falls as shown in the figure The apparent frequency of the sound of the scream as heard by the person A at the top of the building is dependent on time as v is speed of sound A n n n B n n V C v gt 2v n n C n 2v gt 1000

n n n v gt w n 2v4gi n n n n n 2v 2v gt2 A person B accidentally slips from a large building and screams with a sound of constant frequency n as he falls as shown in the figure The apparent frequency of the sound of the scream as heard by the person A at the top of the building is dependent on time as v is speed of sound B 000 000 000 14 26 000 14 26

Question No 45 Single Correct A n n A gt A person B accidentally slips from a large building and screams with a sound of constant frequency n as he falls as shown in the figure The apparent frequency of the sound of the scream as heard by the person A at the top of the building is dependent on time as v is speed of sound LANGUAGE ENGLISH 000 000 Marks 4 00 1 00 CHI

A person B accidentally slips from a large building and screams with a sound of constant frequency n as he falls as shown in the figure The apparent frequency of the sound of the scream as heard by the person A at the top of the building is dependent on time as v is speed of sound A B 000 000 000 000

0 A stationary source emits sound waves of frequency 500 Hz Two observers moving along a line passing through the source detect sound to be of frequencies 480 Hz and 530 Hz Their respective speeds are in ms Take speed of sound 300 m s JEE Main 2019 10 April Shift 1 a 12 16 b 12 18 c 16 14 d 8 18 Exp b Given

In a long cylindrical tube an air column is constructed by fitting a movable piston A tuning fork of frequency 416Hz sends longitudinal sound waves Consider the speed of sound in the air as 333m s It is observed that the air column in the tube vibrates in its fundamental frequency How far from the open end should the piston be in this situation A 10cm B 20cm C 30cm D 40cm

A certain radar operates at a wavelength of 50 cm If the beat frequency between the transmitted signal and the signal reflected from aircraft Af 1kH then what will be the velocity in km h of the aircraft Correct Answer 900

a Find the length of an organ pipe closed at one end that produces a fundamental frequency of 256 Hz when air temperature is 18 0 C b What is its fundamental frequency at 25 0 C We will use the following relation when finding the speed of sound in different temperatures 7331 273