# HANDBOOK OF ACOUSTICS - online book

### A complete view of Acoustical Science & its bearings on music, for musicians & music students.

 EXAMINATION PAPERS.                         281 4.    Describe a stroboscopic method of determining the frequency of a fork. Ans.—See pp. 37 and 38. 5.    What are Combination Tones ? Explain how they are probably produced in the ear when they have no external existence. In what case have they been shown to exist externally, and how ? Ans.—p. 134. The rest of this question is still under discussion. For a full account of the matter, the student is referred to Helmholtz' " Sensations of Tone," 2nd English Edition, pp. 152, and 156 to 159. Also Appendix XX, Section L. TONIC SOL-FA COLLEGE. First Stagb. 1896. 1.   (a) Explain clearly what you understand by a sound-wave P (b)  In what respects may sound-waves differ ? (c)  What difference in the sound results from these differences in the wave? (d)  What is the length of the sound-waves given off from an ordinary tuning-fork ? (e)  Why are the sound-waves from the same fork not always of the same length ? Ans. (a) See pp. 17 and 18. {b) Length, amplitude, and form. (c) Pitch, intensity, and quality. {d) 1100 -h- 517 = 2 ft. 2 in. nearly. {e) Because of temperature. 2.   (a) If a stretched string sounds the note C[, what note will £ of the same string give ? (b) If a certain string stretched by a weight of 25 lbs. gives C, what note will the same string give when stretched by a weight of 9 lbs. Ans. (a) E'. ib) E\>,- 3.   (a) Explain and illustrate the terms "node," and "ventral segment " as applied both to strings and pipes. (b) A closed organ pipe, 2ft. 2ins. long is sounding G in treble staff. Give a sketch showing position of its nodes. Ans. (a) See pp. 96 and 102. Also, nodes in pipes are situated where the changes in density are greatest. (b) See p. 106, fig. 56 B.