If the intensity of sound is doubled, by how many decibels does the sound level increase? (in dB)
Sound wave represented as a displacement wave travels in positive x – direction & y – axis represents particle’s displacement. Match list I with list II COLUMN – I COLUMN – II A 1 P Velocity is along +x axis B 2 Q Velocity is along – x axis C 3 R Velocity is zero D 4 S Acceleration is zero
A sound source is releasing a signal of constant frequency 330 Hz. f& λ are frequency and wavelength observed by an observer. The velocity of sound in air is 330 m s − 1 . Column-I Column-II P The observer & source move towards each other. 1 λ = 1 m , f > 330 Hz Q The observer and source are stationary, wind is blowing towards source from observer. 2 λ = 1 m , f = 330 Hz R The source is stationary, wind is blowing from source to observer and observer is moving away from the source. 3 λ < 1 m , f > 330 Hz S The source is stationary and observer is moving towards source. 4 λ = 1 m , f < 330 Hz
A transverse sinusoidal wave of amplitude a, wavelength λ and frequency f is travelling on stretched string. The maximum speed of any point on the string is v/10, where v is the speed of propagation of the wave. If a = 10 − 3 m and v = 10 m/s, then λ and f are given by
A wire of density 9 × 10 3 kg/m 3 is stretched between two clamps 1 m apart and is stretched to an extension of 4.9 × 10 -4 m. Young’s modulus of material is 9 × 10 10 N m. Then:
Two identical wires are stretched by the same tension of 100 N, and each emits a note of frequency 200 cycles/sec. The tension in one wire is increased by 1 N. Calculate the number of beats heard per second when the wires are plucked.
A triangle wave pulse on a taut string travels in positive x–direction with speed v. the tension in the string is F, and linear mass density of string is μ . At t = 0 the shape of pulse is given by y ( x , 0 ) = 0 if x < − L h ( L + x ) L for − L < x < 0 h ( L − x ) L for 0 < x < L 0 for x > L Choose the INCORRECT statement(s). (h << L)
A transverse sinusoidal wave of amplitude a, wavelength λ and frequency f is travelling on stretched string. The maximum speed of any point on the string is v/10, where v is the speed of propagation of the wave. If a = 10 − 3 m and v = 10 m/s, then λ and f are given by
In resonance tube experiment, a closed organ pipe of length 124 cm resonates when activated by a tuning fork of frequency 340 Hz. If more water is poured in the pipe then [speed of sound in air is 340 m s − 1 ]
Two identical guitar wires have a fundamental frequency of 600 Hz, when kept under the same tension. The tension in a wire can be increased by tightening the tuning keys. During the tightening process, length of vibrating section of wire remains same. What percentage increase in the tension of one of the wires will lead to six beats per second when they are sounded together?
A sonometer wire resonates with a given tuning fork forming standing waves with five antinodes between the two bridges when a mass of 9kg is suspended from the wire. When this mass is replaced by a 25kg mass, the wire resonates with the same tuning fork forming n antinodes for the same positions of the bridges. The value of n is
In a pipe open at two ends a diatomic gas is oscillating in 1st harmonic. The length of the tube is π m and the maximum pressure variation is 1.4 P a . The maximum displacement of gas particles which are a distance of π 3 m from one end is x × 10 − 6 m . The value of x is (Take 1atm= 10 5 Pa)
Shape of string transmitting wave along x-axis at some instant is shown. Velocity of point P is v = 4 π cm/s and θ = tan − 1 0.004 π
Standing waves are established on a string of length L such that A is a node and B is an immediate anti node. Oscillation amplitude for point B is a 0 .Let a ‘ be the oscillation amplitude for point C. Pick the suitable option(s) for correct value of a ‘ and the possible equation(s) for standing waves on the string.
In resonance tube experiment, a closed organ pipe of length 124 cm resonates when activated by a tuning fork of frequency 340 Hz. If more water is poured in the pipe then [speed of sound in air is 340 ms -1 ]
Two identical guitar wires have a fundamental frequency of 600 Hz, when kept under the same tension. The tension in a wire can be increased by tightening the tuning keys. During the tightening process, length of vibrating section of wire remains same. What percentage increase in the tension of one of the wires will lead to six beats per second when they are sounded together?
A sound source is releasing a signal of constant frequency 330 Hz. f& λ are frequency and wavelength observed by an observer. The velocity of sound in air is 330 m s − 1 . Column-I Column-II P The observer & source move towards each other. 1 λ = 1 m , f > 330 Hz Q The observer and source are stationary, wind is blowing towards source from observer. 2 λ = 1 m , f = 330 Hz R The source is stationary, wind is blowing from source to observer and observer is moving away from the source. 3 λ < 1 m , f > 330 Hz S The source is stationary and observer is moving towards source. 4 λ = 1 m , f < 330 Hz
A plane harmonic pressure wave is propagating in air in X-direction. There is a rigid fixed infinitely large wall at yz-plane. The wave gets reflected back by the wall. In this process, the layer of fluid in contact with wall pushes back on the adjacent layer very hard, since it has no where to go. This over – push – back causes the adjacent layer to recoil in the reverse direction, in turn it pushes on its neighbor on the side away from the wall and so on. There is thus a travelling wave that has reverse direction, it has reflected off the wall with no loss of energy. Equation of incident displacement wave is given as S = S 0 sin k x − ω t . (B is Bulk modulus of air), Then
A stationary tuning fork is in resonance with an air column in a pipe. If the tuning fork is moved with a speed of 2 ms −1 in front of the open end of the pipe and parallel to it, the length of the pipe should be changed for the resonance to occur with the moving tuning fork. If the speed of sound in air is 320 ms −1 , the smallest value of the percentage change required in the length of the pipe is
Two identical pulses (one is inverted w.r.t other) move in opposite directions with same uniform speeds on a stretched string. The width and kinetic energy of each pulse are L and k respectively. At the instant they completely overlap, the kinetic energy of the width L of the string in overlapped part is
Two wires are fixed on a sonometer. Their tensions are in the ratio 8 :1, their lengths are in the ratio 36:35, the diameters are in the ratio 4:1 and densities are in the ratio 1:2. If the value of higher frequency is 36Hz, then lower frequency is p × q H z , here both p a n d q are integers. The value of p – q is
String of length L whose one end is x = 0 vibrates according to the relations given in column-I. Select matching entries from column-lI including nodes or antinodes at the end points of string. Column-I Column-II (a) y = Asin πx L sin ωt (p) 1 antinode, 2 nodes (b) y = Acos πx L sin ωt (q) 3 nodes, 2 antinodes (c) y = Asin 2 πx L sin ωt (r) 2 antinodes, 1 node (d) y = Acos 2 πx L sin ωt (s) 3 antinodes, 2 nodes
A wave equation which gives the displacement along the Y direction is given by the equation y = 10 4 sin ( 60 t + 2 x ) , where x and y are in metres and t is time in seconds. This represents a wave
Two waves of equal frequency f and velocity v travel in opposite directions along the same path. The waves have amplitudes A and 3A. Then
The speed of a transverse wave, going on a wire having a length 50 cm and mass 5 g is 80 m/s. The area of cross section of the wire is 1.0 mm 2 and its Young’s modulus is 8 × 10 11 N / m 2 . Find the extension in × 10 − 2 mm of the wire over its natural length.
A wave equation which gives the displacement along Y-direction is given by y = 10 − 4 sin ( 60 t + 2 x ) where x and y are in metres and t is time in seconds. This represents a wave
Velocity of sound in air is 320 m/s. A pipe closed at one end has a length of l m. Neglecting the corrections, the air column in the pipe can resonate for sound of frequency
A wave equation which gives the displacement along Y-direction is given by y = 10 − 4 sin ( 60 t + 2 x ) where x and y are in metres and t is time in seconds. This represents a wave
A loudspeaker that produces signals from 50 to 500 Hz is placed at the open end of a closed tube of length 1.1 m. The lowest and the highest frequency that excites resonance in the tube are f l and f h , respectively. The velocity of sound is 330 m/s. Then
An open organ pipe has a fundamental frequency of 330 Hz. The first overtone of a closed organ pipe has the same frequency as the first overtone of an open pipe. What is the length of closed organ pipe (in cm)? (Speed of sound in air = 330 m/s)
The speed of a transverse wave, going on a wire having a length 50 cm and mass 5.0 kg, is 80 m/s. The area of cross-section of the wire is 1.0 mm 2 and its Young’s modulus is 16 × 10 11 N / m 2 . Find the extension of the wire over its natural length (in mm).
A tube of certain diameter and of length 48 cm is open at both ends. Its fundamental frequency of resonance is found to be 320 Hz. The velocity of sound in air is 320 m/s. One end of the tube is now closed, considering the effect of end correction, calculate the lowest frequency of resonance for the tube (in Hz).
Two wires are fixed on a sonometer wire. Their tensions are in the ratio 8:1, the lengths in the ratio 36:35, the diameters in the ratio 4:1 and the densities in the ratio 1:2. Find the frequency of the beats (in Hz) produced if the note of the higher pitch has frequency of 360 Hz.
When both source and observer approach each other with a speed equal to the half the speed of sound, then determine the percentage change in frequency of sound as detected by the listener.
