Two organ pipes closed at one end produce \(5\) beats per second in fundamental mode. If the ratio of their lengths is \(10:11\), then their frequencies (in Hz) are:

Two sitar strings, \(A\) and \(B,\) playing the note \(\mathrm{Ga},\) are slightly out of tune and produce \(6~\text{Hz}\) beats. The tension in the string \(A\) is slightly reduced, and the beat frequency is found to be reduced to \(3~\text{Hz}.\) If the original frequency of \(A\) is \(324~\text{Hz},\) what is the frequency of \(B?\)

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:

Two wires, \(A\) and \(B,\) of a musical instrument 'Sitar' produce \(3\) beats per second. If the tension of \(B\) is raised, the number of beats becomes \(1\) beat per second. If the frequency of \(A\) is \(450~\text{Hz}\), then the original frequency of \(B\) will be:
1. \(447~\text{Hz}\)
2. \(453~\text{Hz}\)
3. \(449~\text{Hz}\)
4. \(451~\text{Hz}\)

A student tunes his guitar by striking a \(120~\text{Hz}\) with a tuning fork and playing the \(4^{\text{th}}\) string at the same time. By keen observation, he hears the amplitude of the combined sound oscillating thrice per second. Which of the following frequencies is most likely the frequency of the \(4^{\text{th}}\) string on his guitar?
1. \(130\)
2. \(117\)
3. \(110\)
4. \(120\)

Two sound waves with wavelengths \(5.0~\text{m}\) and \(5.5~\text{m}\), respectively, propagate in gas with a velocity of \(330~\text{m/s}\). How many beats per second can we expect?
1. \(12\)
2. \(0\)
3. \(1\)
4. \(6\)