Sound as a Pressure Wave

IMPORTANT

Sound as a Pressure Wave: Overview

This topic covers concepts, such as, Displacement Function for a Longitudinal Wave, Sinusoidal Waves in Solids and Liquids, Pressure Equation of Sound Wave & Relation between Pressure and Displacement Amplitudes etc.

Important Questions on Sound as a Pressure Wave

MEDIUM
IMPORTANT

Which of the following equations does not represent a progressive wave?

EASY
IMPORTANT

Equation of a longitudinal wave is given as s=10-2sin2π1000t+50x17(all SI units). Find the location x (in m), at t=0, where the magnitude of the change in pressure is maximum.

MEDIUM
IMPORTANT

The phase difference between displacement and particle velocity is

MEDIUM
IMPORTANT

The phase difference between displacement and pressure wave equation of longitudinal wave.

MEDIUM
IMPORTANT

If mean coordinate the particle of longitudinal wave be xm then minimum coordinate of displacement will be.

MEDIUM
IMPORTANT

If mean co-ordinate of the particle of longitudinal wave be xm, then what will be maximum co-ordinate of displacement (a = amplitude)

MEDIUM
IMPORTANT

A displacement versus time graph (s-tgraph) is as shown for particles at x=0, for a sound wave which is propagating towards left. (negative x-axis)

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If P is change in pressure, then choose correct matching of the graphs.

 

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HARD
IMPORTANT

A small speaker has a capacity of power 3 W. A microphone is placed at distance 2 m from the speaker. Find the displacement amplitude of particles of air near the microphone. The frequency of sound emitted by the speaker is 1 kHz. (Density of air = 1.2 kg m-3 and speed of sound in air = 330 m s-1 )

HARD
IMPORTANT

If given graph represents the variation of displacement wave for sound wave in an air tube. Which will be the pressure variation for tube?
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MEDIUM
IMPORTANT

The equation of a sound wave in air is

P=0.01cos1000t-3x

where P, x and t are in SI units. The bulk modulus of elasticity is 1.4×105 N m-2. The displacement amplitude is

EASY
IMPORTANT

The displacement y of a particle in a medium can be expressed as :
y=10-6sin100t-20x+π/4 m, where t is in second and x in meter. The speed of the wave is