Superposition of Waves

IMPORTANT

Superposition of Waves: Overview

This topic covers concepts, such as, Reflection and Transmission of Waves, Reflection of Waves at Fixed Ends, Equation of Resultant Sound Wave after Interference & Quincke's Tube etc.

Important Questions on Superposition of Waves

EASY
IMPORTANT

The equations of two waves are given by :

y1=5sin2πx-vt cm

y2=3sin2πx-vt+1.5 cm

These waves are simultaneously passing through a string. The amplitude of the resulting wave is :

HARD
IMPORTANT

The interference pattern is obtained with two coherent light sources of intensity ratio 4:1. And the ratio Imax+IminImax-Imin is 5x. Then, the value of x will be equal to :

EASY
IMPORTANT

Two light beams of intensities in the ratio of 9:4 are allowed to interfere. The ratio of the intensity of maxima and minima will be :

HARD
IMPORTANT

Two sound waves of frequencies 100 Hz and 102 Hz and having same amplitude 'A' are interfering. A stationary detector, which can detect waves of amplitude greater than or equal to A. So, in a given time interval of 12 seconds, find the total duration in which detector is active.

HARD
IMPORTANT

A loud speaker L is placed in long narrow hall with two doors D1 and D2 open to the very long play ground as shown in figure. The distanceD1D2 is 12 m, distance between two parallel walls of hall is 9 m. The loud speaker is fitted to the wall on a line perpendicular to D1D2 which passes through door D2. On same line one interference maxima is obtained at P at distance 9 m from door D2. It is known that loud speaker emits monotomic sound of frequency 150 Hz, and because of presence of some other gas in hall and bit high temperature speed of sound waves in hall is 450 ms-1 while in air in ground is 300 ms-1.

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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

HARD
IMPORTANT

There are three strings RP, PQ, QS as shown in the figure. Their mass and lengths are RP=0.1 kg,2 m,PQ=0.2 kg,3 m,QS=0.15 kg,4 m respectively. All the strings are under same tension. Wave-1 travelling in RP is incident at P. It is partly reflected (Wave-2) and partly transmitted (wave-3). Now wave-3 is incident at Q. It is again partly transmitted (wave-5) and partly reflected (wave-4). Choose the CORRECT option(s).

("A" is amplitude of corresponding waves, v represents corresponding wave speeds)

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EASY
IMPORTANT

Two waves, each with an amplitude of 0.5m are superimposed with constructive interference such that they are in phase. What is the resultant amplitude?

EASY
IMPORTANT

When two progressive waves y1=4sin(2x-6t) and y2=5sin2x-6t-π2 are superimposed, the amplitude of the resultant wave is x unit.  Find the value of x.

MEDIUM
IMPORTANT

Two identical sources of sound S1 and S2 produce intensity I0 at a point P equi distant from source. If power of S1 is reduced to 64% and phase difference between two sources is varied then let Imax is maximum intensity at point P. Find 100×ImaxI0.

HARD
IMPORTANT

Two speakers connected to the same source of fixed frequency are placed 2 m apart in a box. A sensitive microphone placed at a distance of 4 m from their midpoint along the perpendicular bisector shows a maximum response. The box is slowly rotated until the speakers are in line with the microphone. The distance between the midpoint of the speakers and the microphone remains the same. Exactly five maximum responses are observed in the microphone in doing this. The wavelength of sound wave is (in m):

EASY
IMPORTANT

A wave represented by the equation y=acoskx-ωt is superposed with another wave to form a stationary wave such that the point x=0 is a node. The equation of the other wave is,

EASY
IMPORTANT

A man standing on a cliff claps his hand hears its echo after 1 s. If sound is reflected from mountain and velocity of sound in air is 340 m s-1. Then, the distance between the man and reflection point is,

MEDIUM
IMPORTANT

Phase difference between the incident and reflected wave, when the reflection happens at fixed end:

HARD
IMPORTANT

Two loudspeakers L1 and L2 driven by a common oscillator and amplifier are arranged as shown. The frequency of the oscillator is gradually increased from zero and the detector at D records a series of maxima and minima. If the speed of sound is 330 m s-1, then the frequency at which the first maximum is observed is

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MEDIUM
IMPORTANT

An observer receives waves directly from a source of sound distant 120 m in a big hall. He also receives waves reflected from the mid-point of 25 m high ceiling. The wavelength of sound for constructive interference to take place between two waves, must be

EASY
IMPORTANT

An organ pipe open at both ends produces:

MEDIUM
IMPORTANT

The disturbances produced by two sound sources cannot be cancelled as the disturbance by each wave is added.

MEDIUM
IMPORTANT

What do you understand by principle of superposition of waves?

HARD
IMPORTANT

Describe the reflection of the wave from a free end.