A source of unknown frequency gives \(4\) beats/s when sounded with a source of known frequency of \(250~\text{Hz}\). The second harmonic of the source of unknown frequency gives five beats per second when sounded with a source of frequency of \(513~\text{Hz}\). The unknown frequency will be:
1. | \(246~\text{Hz}\) | 2. | \(240~\text{Hz}\) |
3. | \(260~\text{Hz}\) | 4. | \(254~\text{Hz}\) |
Two sources of sound placed close to each other, are emitting progressive waves given by,
\(y_1=4\sin 600\pi t\) and \(y_2=5\sin 608\pi t\).
An observer located near these two sources of sound will hear:
1. | \(4\) beats per second with intensity ratio \(25:16\) between waxing and waning |
2. | \(8\) beats per second with intensity ratio \(25:16\) between waxing and waning |
3. | \(8\) beats per second with intensity ratio \(81:1\) between waxing and waning |
4. | \(4\) beats per second with intensity ratio \(81:1\) between waxing and waning |
Two identical piano wires, kept under the same tension T, have a fundamental frequency of 600 Hz. The fractional increase in the tension of one of the wires which will lead to the occurrence of 6 beats/s when both the wires oscillate together would be:
1. 0.01
2. 0.02
3. 0.03
4. 0.04
A tuning fork of frequency \(512\) Hz makes \(4\) beats/s with the vibrating string of a piano. The beat frequency decreases to \(2\) beats/s when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was:
1. \(510\) Hz
2. \(514\) Hz
3. \(516\) Hz
4. \(508\) Hz
Each of the two strings of lengths 51.6 cm and 49.1 cm is tensioned separately by 20 N of force. The mass per unit length of both strings is the same and equals 1 g/m. When both the strings vibrate simultaneously, the number of beats is:
1. | 5 | 2. | 7 |
3. | 8 | 4. | 3 |
Two sound waves with wavelengths 5.0 m and 5.5 m, respectively, propagate in gas with a velocity of 330 m/s. How many beats per second can we expect?
1. 12
2. 0
3. 1
4. 6