A uniform rope of length \(L\) and mass \(m_1\) hangs vertically from a rigid support. A block of mass \(m_2\) is attached to the free end of the ropes. A transverse pulse of wavelength \(\lambda_1\) is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is \(\lambda_2\). The ratio \(\dfrac{\lambda_2}{\lambda_1}\) is:
1. \(\sqrt{\dfrac{m_1+m_2}{m_1}}\)
2. \(\sqrt{\dfrac{m_2}{m_1}}\)
3. \(\sqrt{\dfrac{m_1+m_2}{m_2}}\)
4. \(\sqrt{\dfrac{m_1}{m_2}}\)
A source of sound S emitting waves of frequency 100 Hz and an observer O are located at some distance from each other. The source is moving with a speed of 19.4 ms-1 at an angle of 60° with the source observer line as shown in the figure. The observer is at rest. The apparent frequency observed by the observer (velocity of sound to air 330 ms-1), is
1. 100 Hz
2. 103Hz
3. 106 Hz
4. 97 Hz
4.0 g of a gas occupies 22.4 L at NTP. The specific heat capacity of the gas at constant volume is 5.0 J K-1mol-1. If the speed of sound in this gas at NTP is, then the heat capacity at constant pressure is: (Take gas constant R=8.3 JK-1mol-1)
1. 8.0 JK-1mol-1
2. 7.5 JK-1mol-1
3. 7.0 JK-1mol-1
4. 8.5 JK-1mol-1
1. | \(155~\text{Hz}\) | 2. | \(205~\text{Hz}\) |
3. | \(10.5~\text{Hz}\) | 4. | \(105~\text{Hz}\) |
If n1, n2 and n3 are, are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency n of the string is given by
1. 1/n=1/n1+1/n2+1/n3
2. 1/√n=1/√n1+1/√n2+1/√n3
3. √n=√n1+√n2+√n3
4. n=n1+n2+n3
1. | \(4\) | 2. | \(5\) |
3. | \(7\) | 4. | \(6\) |
A speed motorcyclist sees a traffic jam ahead of him. He slows down to 36km/h. He finds that traffic has eased and a car moving in front of him at 18km/h is honking at a frequency of 1392Hz. If the speed of sound is 343m/s, the frequency of the honk as heard by him will be
1. 1332Hz
2. 1372Hz
3. 1412Hz
4. 1454Hz
A wave travelling in the positive x-direction having maximum displacement along y-direction as 1m, wavelength 2π m and frequency of 1/π Hz is represented by
1. y=sin(x-2t)
2. y=sin(2πx-2πt)
3. y=sin(10πx-20πt)
4. y=sin(2πx+2πt)
If we study the vibration of a pipe open at both ends. then the following statements is not true
1. Open end will be anti-node
2. Odd harmonics of the fundamental frequency will be generated
3. All harmonics of the fundamental frequency will be generated
4. Pressure change will be maximum at both ends
A source of unknown frequency gives 4 beats/s when sounded with a source of known frequency 250 Hz. The second harmonic of the source of unknown frequency gives five beats per second when sounded with a source of frequency 513 Hz. The unknown frequency is
1. 254 Hz
2. 246 Hz
3. 240 Hz
4. 260 Hz