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mperature, , 5 : * tel, ; in air at room, Aim : (i) To determine the speed of sound in ni, (ii) To-find-out-the-unkn, , ce tube, set of tuning forks, retor sy., , Apparatus : er, resonan', , A long plastic jar filled with — an, meter scale, vernier calliper, rubber p, , Diagram :, , Tuning fork |, , , , , , , , Formula:, (i) End correction e = 0,3d where d is the inner diameter of resonance tube, , (ii) V=4 (nL). n= frequency of tuning fork, = 4n (+e), , = 4n (€+0.3d) £ = observed Tesonating length of air column, Gi) Vs4x 1 (if graph is i against n), L, , L = correct Tesonating length of air column, , slope, (iv) (nL) mean (where L j, n= } Te L. is the correct Tesonating length for fork, ‘e of unknown frequency), Procedure:, , scanned witn Lamscanne
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——, , 4, Immerse the resonance tube i, , in the plastic j ; ‘, length of the air column is i Plastic jar filled with water as deep as possible so that the, , oe nimum., 5. eae the tuning forks in descending order of frequency., trike the tuni ; ., , 6. ffl wate fork of highest frequency gently on the rubber pad and hold it near the mouth, Risieerthe vesone tube, So that the prong of the tuning fork vibrate in vertical plane., , 7 he air col nance tube slowly along with the fork till a loud sound is heard indicating that, the ‘arco cf 1s vibrating in resonance with the fork. Clamp the tube., , 8. Measure the length of air column from the surface of the water level to the open end of the, resonance tube using meter scale ., , 9. Repeat the procedure and Measure the length (£) three times for the same tuning fork and, calculate mean length (2), , 10. Set the next tuning fork in to vibrations, hold it near the open end of the resonance tube, raise, it slowly from the previous Position till resonance is obtained and measure the corresponding, length (€) three times and calculate the mean length “py, , 11. Repeat the complete procedure fir the rest of the tuning forks +4, , 12. Similarly find the mean resonating length (¢,) for the unknown frequency tuning fork (n,), , 13. Add end correction (e) to mean Tesonating length (£).an¢f calculate corrected length (L) for all, tuning forks. Calculate L, for the tuning fork of unknown frequency, , 14, Calculate nL for all tuning forks except the tuning fork of unknown frequency, , 15. Calculate the speed of sound at room temperature and also unknown frequency, 16. Plot a graph of n (y axis) against dé axsis) and calcualte the speed of sound by graph., L, , Observations :, , 1, Least count of vernier calliper, (i) Smallest division on the main scale of vernier calliper,, (ii) Total number of divisions on the vernier scale of the vernier calliper, y= «AD... div., (iii) Least count (L.C) of vernier calliper, x/y = 89.1. cm a, (iv) Zero error (e')= ...Q....cm, , x= 0:00 cm, , , , , Observation table :, 1) For inner diameter of resonance tube, , , , MSR /(a)cm VSD VSR Diameter / Corrected, (b)cem (c=bx L.C) (total reading) reading, cm (atc = d') cm (d=d'—e')cm, , , , , , , , , , 2 v4 | a4 QG, >To 2.12 | ode jal BIAS, Ex a a 2.13, , f Mean d= 91)4.cm, End correction e = 0.3 d ar ail, , scanned with Vamscann, , , , , , ro b>
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cacueom ., , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , — Logn LogL yn, © (b), a taaraiciciinal, Mean (nL) = 8 |: ;, , (1) Speed of Sound (ot) = BGI 2 Hz-em or em/s, , V=4(nL). on, , =4x BALD, , = 2152,8Hz cm or cm/s 23253246,, (2) Unknown frequency, , ai = _ mean (nL), Corrected length corresponding to the unknown frequency d,), =____ Hz, , Result :, , 1) Speed of sound in air at room temperature, a) By calculation : V =4 150245, b) By-graph_—+—¥-= ams, 2) Unknown frequency of fork, a) By calcula, b) By graph, , , , , Precautions:, 1. Strike the tuning fork gently on rubber pad, . Hold the vibrating tuning fork just above the mouth of the resonance tube, , 2Z, 3. Do not bring ear close to the tube 7, 4. While adjusting the resonating length, start with the minimum length of the air column and the, , tuning fork of highest frequency, . Tuning fork should not touch the resonance tube ;, 6. The prongs of the tuning fork must vibrate in vertical plane, , 2, 1. What is meant by the term resonance *, , an, , , , , _D, scanned witn Gamscann
