A standing wave is formed by the superposition of two waves traveling in opposite directions. The transverse displacement is given by \(y(x,t)=0.5\sin\left(\frac{5\pi}{4}x\right) \cos(200\pi t).\) What is the speed of the traveling wave moving in the positive \(x\) direction?
\((x\) and \(t\) are in meters and seconds, respectively.)
1. \(180~\text{m/s}\)
2. \(160~\text{m/s}\)
3. \(120~\text{m/s}\)
4. \(90~\text{m/s}\)
Subtopic:  Standing Waves |
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A pipe of length \(11~\text{cm}\) is closed at one end. The first harmonic frequency of the pipe in the air at \(0^\circ \text{C}\) is:
(the velocity of sound at \(0^\circ \text{C}=330~\text{m/s}\))
1. \(1200~\text{Hz}\)
2. \(1000~\text{Hz}\)
3. \(800~\text{Hz}\)
4. \(750~\text{Hz}\)
Subtopic:  Standing Waves |
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A string is fixed at both ends and set to vibrate in five loops. If the wavelength is \(8\) cm then the length of the string is:
1. \(10 \) cm
2. \(15\) cm
3. \(20\) cm
4. \(25\) cm

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If the speed of sound in air is \(v,\) then the minimum possible length of the closed-end organ pipe which resonates to frequency \(f\) will be:

1. \(\dfrac{v}{2f}\) 2. \(\dfrac{v}{4f}\)
3. \(\dfrac{v}{3f}\) 4. \(\dfrac{v}{f}\)
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Two waves executing simple harmonic motion travelling in the same direction with the same amplitude and frequency are superimposed. The resultant amplitude is equal to the \(\sqrt 3 \) times of amplitude of individual motions. The phase difference between the two motions is:
1. \(30^{\circ}\) 2. \(45^{\circ}\)
3. \(60^{\circ}\) 4. \(90^{\circ}\)
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When a string is divided into three segments of lengths \(l_1\), \(l_2\) and \(l_3\), the fundamental frequencies of these three segments are \(\nu_1\), \(\nu_2\) and \(\nu_3\) respectively. The original fundamental frequency (\(\nu\)) of the string is:

1. \(\sqrt{\nu} = \sqrt{\nu_1}+\sqrt{\nu_2}+\sqrt{\nu_3}\)
2. \(\nu = \nu_1+\nu_2+\nu_3\)
3. \(\dfrac{1}{\nu} =\dfrac{1}{\nu_1} +\dfrac{1}{\nu_2}+\dfrac{1}{\nu_3}\)
4. \(\dfrac{1}{\sqrt{\nu}} =\dfrac{1}{\sqrt{\nu_1}} +\dfrac{1}{\sqrt{\nu_2}}+\dfrac{1}{\sqrt{\nu_3}}\)
Subtopic:  Standing Waves |
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AIPMT - 2012
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A string, under tension, and lying along the \(x\)-axis is set into transverse vibrations. The displacement at a point \(x\) is given by the function \(y(x,t)\) where \(t\) represents the time:    \(y(x,t)=\left ( 3~\text{mm} \right )\mathrm{sin}\left ( \frac{\pi x}{20~\text{cm}} \right ) \)\(\mathrm{cos}\left\{2\pi\left ( 100~\text{s}^{-1} \right )t \right\}\)
The maximum amplitude of vibration at any point on the string is:
1. \(3~\text{mm}\)
2. \(20~\text{cm}\)
3. \(300~\text{mm}\)
4. \(15~\text{mm}\)
Subtopic:  Standing Waves |
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A pipe is \(15\) cm long and is open at both ends. Which harmonic mode of the pipe will resonate with a \(2.2\) kHz sound source?
(Given: the velocity of sound in air \(=330\) m/s)

1. fundamental 2. second harmonic
3. third harmonic 4. fourth harmonic
Subtopic:  Standing Waves |
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A string is stretched between fixed points separated by \(75.0~\text{cm}\). It is observed to have resonant frequencies of \(420~\text{Hz}\) and \(315~\text{Hz}\). There are no other resonant frequencies between these two. The lowest resonant frequency for this string is:
1. \( 155~\text{Hz} \) 2. \( 205~\text{Hz} \)
3. \( 10.5~\text{Hz} \) 4. \( 105~\text{Hz} \)
Subtopic:  Standing Waves |
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NEET - 2015
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Which of the following statements are true for a stationary wave?
(a) Every particle has a fixed amplitude which is different from the amplitude of its nearest particle.
(b) All the particles cross their mean position at the same time.
(c) All the particles are oscillating with same amplitude.
(d) There is no net transfer of energy across any plane.
(e) There are some particles which are always at rest.
Choose the correct option:
1. (a), (c)
2. (a), (b), (d), (e)
3. (b), (d)
4. (c), (d)
Subtopic:  Standing Waves |
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