Progressive and Stationary Waves

IMPORTANT

Progressive and Stationary Waves: Overview

This topic covers concepts, such as, Standing Waves, Equation of Standing Waves, Decibel Scale of Sound Waves & Equation of Standing Waves in Sonometer etc.

Important Questions on Progressive and Stationary Waves

MEDIUM
IMPORTANT

In a sonometer wire the tension is maintained by suspending a 50.7 kg mass from the free end of the wire. The suspended mass has volume of 0.0075m​3. The fundamental frequency of the wire is 260Hz. Find the new fundamental frequency if the suspended mass is completely submerged in water

MEDIUM
IMPORTANT

A string of length 1 m and mass 2×105 kg is under tension T. When the string vibrates, two successive harmonics are found to occur at frequencies 750 Hz and 1000 Hz. The value of tension T is _____ newton.

EASY
IMPORTANT

A part of snapshot of progressive wave propagating in a uniform string is shown in figure-1 and a snapshot of standing wave in a string (identical to case-1) is shown in figure -2.
The amplitude, frequency and wave length of waves in both cases is same. A and B (anti node) are material cross-section on strings. At the instant shown both A&B are at their respective maximum displacement. dE represents wave energy of small element of length dx.

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MEDIUM
IMPORTANT

A disc placed on a frictionless horizontal plank is rotating with a constant angular velocity ω about its central vertical axis. Now the plank is made to move with a constant acceleration α on a straight path. If you assume initial location of the centre of disc as origin, direction of motion of the plank in negative y-axis of the coordinate system attached with the plank, which of the following equations represent trajectroy of instantaneous centre of rotation of the disc.

MEDIUM
IMPORTANT

The tension in a stretched string fixed at both ends is changed by 2%, The fundamental frequency is found to get changed by 15 Hz. Select the correct statement(s):

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HARD
IMPORTANT

A string is stretched between a pulley and a wave generator consisting of a plate vibrating up and down with small amplitude and frequency 120 Hz. The standing wave pattern has 4 nodes as shown. What should be the load (in gm) we want a standing wave with 5 nodes.

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MEDIUM
IMPORTANT

The equation of a wave on a string of linear mass density 0.04 kg m-1 is given by,  y=0.02msin2πt0.04(s)-x0.50(m).

The tension in the string is n×10-2 N. Write the value of n.

HARD
IMPORTANT

A string of length 1.5 m with its two ends clamped is vibrating in the fundamental mode. The amplitude at the centre of the string is 4 mm. The minimum distance between the two points having amplitude of 2 mm is:

HARD
IMPORTANT

One end of a uniform string is attached to an oscillator which is oscillating along y axis according to the law y=t-[t]2n<t<2n+102n+1<t<2n+2
Where y is in meters, t is in seconds and n=0,1,2,3. Other end of string is fixed to rigid wall. Tension in the string is 25 N, mass of string is 10 kg and length is 10 m Let oscillator be placed at origin and wall is at x=10 then answer following question. {Assume gravity free space and no damping}

MEDIUM
IMPORTANT

The tension in a stretched string fixed at both ends is increased by 2%, the fundamental frequency is found to get increased by 15 Hz. Select the correct statement(s):

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MEDIUM
IMPORTANT

A rod of length0.3 m having variable linear mass density from A to B as λ=λ0x(x is distance from A in meter), where λ0=100 kgm-2 is suspended by two light wires of same length. Ratio of linear mass density of wire- 1 and wire- 2 is 2: 9

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Then which of the following is/are CORRECT:

MEDIUM
IMPORTANT

A long wire PQR is made by joining two wires PQ and QR of equal radii. PQ has a length 4.8 m and mass 0.06 kg. QR has length 2.56 m and mass 0.2 kg. The wire PQR is under a tension of 80 N. A sinusoidal wave pulse of amplitude 3.5 cm is sent along the wire PQ from the end P. No power is dissipated during the propagation of wave pulse. Find amplitude (in mm) of reflected pulse from junction Q.

MEDIUM
IMPORTANT

A string will break apart if it is placed under too much tensile stress. One type of steel has density. ρsteel =104 kg m-3 and breaking stress α=9×108 N m-2. We make a guitar string from 4π gram of this type of steel. It should be able to withstand 900πN without breaking. What is highest possible fundamental frequency (in Hz ) of standing waves on the string if the entire length of the string vibrates?

MEDIUM
IMPORTANT

A transverse wave is travelling on a string with speed v. The shape of string at t=1sec is given by y=5x2+6x+9 and at t=2sec, it is given by y=5x2+12x+36, then fill the value of v+c, where c is number that denotes the direction of motion of wave (+1 for positive x-direction and -1 for -vex-direction). (Consider SI units through out)

MEDIUM
IMPORTANT

Choose correct statements

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MEDIUM
IMPORTANT

Three simple harmonic waves, identical in frequency n and amplitude A moving in the same direction are superimposed in air in such a way, that the first, second and the third wave have the phase angles ϕ,ϕ+π2 and ϕ+π, respectively at a given point P in the superposition. Then as the waves progress, the superposition will result in

MEDIUM
IMPORTANT

A part of snapshot of progressive wave propagating in a uniform string is shown in figure-1 and a snapshot of standing wave in a string (identical to case-1) is shown in figure -2. The amplitude, frequency and wave length of waves in both cases is same. A and B (anti node) are fixed cross-section on strings. At the instant shown both AB are at their respective maximum displacement. 'E' represents energy of wave.

 

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MEDIUM
IMPORTANT

A part of snapshot of progressive wave propagating in a uniform string is shown in figure-1 and a snapshot of standing wave in a string (identical to case-1) is shown in figure -2.
The amplitude, frequency and wave length of waves in both cases is same. A and B (anti node) are fixed cross-section on strings. At the instant shown both A&B are at their respective maximum displacement. 'E' represents energy of wave.

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MEDIUM
IMPORTANT

A plane progressive transversal mechanical wave is advanced in a medium along the +x-axis in the ground frame of reference is represented by the equation y=Asinωt-kx then which of the following statements are correct?

MEDIUM
IMPORTANT

The equation of a one dimensional transverse wave is given by ψ=10-3sinπ10t-3x-2y+z where x,y and ψ are expressed in meter and t in second Choose the correct option(s)