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temperature, , und in ait ut rood ”, “ fork usitiy HesonaucsLulieg, , Aim; i to determine the specd of ’, : of orteminigy, —_ (i) -Fe-find-ont the unknomstrequency, , Apparatus : 14 ' spit aPiiimtan BAA. Fa, " Along plastic jar filled with water, resonanee tube, set of tuning forks, retort xy, , meter scale, vernler caliper, rubber pad, thermometer, , Diagram : mettre a, , ( Tunips fork, , +— Stand, , , , A auneuguengent, aNowedoae, , , , , , , , , , , , L, , 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 (f+e) L = correct resonating length of air column, , = 4n (€+0.3d) € = observed resonating length of air column, (iii) Ve4ax_] (if graph is 1 against 1), , slope L, , (iv) A= (nL) mean (where L, is the correct resonating length for for, , . L, , " of unknown frequency), , Procedure :, , 1. Measure the inner diameter of the resonance tube with the help of the upper jaws of vei, calliper. Take three readings and hence calculate end correction of resonance tube,, , 2. Note down the room temperature using the given thermometer,, , 3. Hold the resonance tube vertically in the plastic jar filled with water with the help of n, , stand ( as shown in the diagram)., , scanned witn Lamscanne
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4, Immerse the resonance tube in the, , ‘ Plastic jar filled with water as deep as possible so that the, length of the air column is minimu, , m., 5. Arrange the tuning forks in descending order of frequency., 6. Strike the tuning fork of highest fre,, , of the resonance tube, so that the p, 7. Raise the resonance tube slowl, , the air column is vibrating in Fesonance with the fork. Clamp the tube,, , 8. Measure the length of alr column from tlie surface of thé water-level to the opén end of the, resonance tube using meter scale, , 9, Repeat the procedure and metsure the |, calculate mean length ye. 4, , quency gently on the rubber pad and hold it near the mouth, , a : wi, length (£) three times for the same tuning fork and, , t be ra ., , it near the open end of the resonance tube, raise, , : ceis obtained and measure the corresponding, ‘length (£) three timeg arid calculate the mean length, , 1, Repeat the complete procedure for the rest of the tuning forks s+. 0.5,, , soe a, 12. Similarly tind the mean resonating length (,) for,the unknown frequency tuning fork (n,), 13. Add end correction (e) to mean resonating length (£) and calculate corrected length (L) for all, tuning fork of inknown frequency, , 16. Plot a graph of n (y axis) against te 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, x= .O.* 1 cm, (ii) Total number of divisions on the vernier scale of the vernier calliper, y= ..J.O div,, (iii) Least count (L.C) of vernier calliper, x/y = 0! cm, (iv) Zero error (e')= ....0...cm, Observation table :, !) For inner diameter of resonance tube, VSD PV SRP soe Diameter /_, (b)em | (c=bxL.C) | (total reading), (ate =d') cm, , 4 Q:04 | Q.04, 2 0-03 a0, a. ood Aso2,, , , , , , , , , , , , , , , , , , , , , , , , , , , , End correction ¢ = 0.3 d 0: 64 ems, , any Scanned witn Camscann
Page 5 : Caleulations, , , , , , , , , , , , , , , , , , , , , , , , Mean (nL) =, (1) Speed of Sound oh —Hzem or cm/s, V=4(0L),..,, =4x Ere ZS: pase, =22)882Hz cm or cm/s m/s, , , , (2) Unknown frequency, n = mean (aL), Corrected length corresponding to the unknown frequency ,), = ____ Hz, , Result :, 1) Speed of sound in air at room tem, gag, , a) By calculation : v =33!, , 6} By-graph—__V_ = lee, 2) Unknown frequency of fork, , a) By caleculatioi : Hz, , b) By graph Zz, Precautions:, , I. Strike the tuning fork gently on rubber pad, , 2. Hold the vibrating tuning fork just above the mouth of the resonance tube, , 3. Do not bring ear close to the tube ;, , 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, , a, , <a, , scanned witn Lamscanne
