ultrasonic interferometer pankaj yadav (4)_FPI[1][1].pptx

Ultrasonic interferometer

1. DEEN DAYAL UPADHYAYA G0RAKHPUR UNIVERSITY Department of Physics Session 2022-23 TOPIC: ULTRASONIC INTERFEROMETER Name- Pankaj Yadav Class-M.Sc. 3 rd Sem ( Biophysics) Roll no-2213050010020 Under the guidance of : Dr. Ambrish Kumar Srivastava ( Asst. Prof. DDUGU)

2. Contents OBJECT APPARATUS USED FORMULA USED THEORY OBSERVATIONS RESULT REFERENCES

3. Object: To determine the velocity of the ultrasonic wave in benzene liquid and determine the compressibility of benzene liquid. FORMULA USED : (A): wavelength of ultrasonic wave : λ=2d (B ): velocity of ultrasonic waves in a given liquid: v = f. λ (C): compressibility : ß=1/ ρv 2 w here, ρ is density of liquid APPARATUS : Ultrasonic interferometer, sample liquids, high frequency generator etc.

4. THEORY ULTRASONIC INTERFEROMETER : An Ultrasonic Interferometer is a simple and direct device to determine the ultrasonic velocity in liquids with a high degree of accuracy. The apparatus consists of an ultrasonic cell, which is a double walled brass cell with chromium plated surfaces having a capacity of 10ml. The double wall allows water circulation around the experimental medium to maintain it at a known constant temperature. The principle used in the measurement of velocity (V) is based on the accurate determination of the wavelength (λ) in the medium. Ultrasonic sound refers to sound pressure with a frequency greater than the human audible range (20Hz to 20 MHz)

5. Fig. Experimental Setup

6. Generation of ultrasound:   Piezoelectric generator :     This is the most common method used for the production of ultrasound. When mechanical pressure is applied to opposite faces of certain crystals which are cut suitably, electric fields are produced. Similarly, when subjected to an electric field, these crystals contract or expand, depending on the direction of the field. Thus a properly oriented rapid alternating electric field causes a piezoelectric crystal to vibrate mechanically. This vibration, largest when the crystal is at resonance, is used to produce a longitudinal wave,  i.e. , a sound wave.

7. Procedure for performing lab: Unscrew the cap of the cell and lift it away. Fill the middle portion with the experimental liquid and screw the cap tightly. Then connect the high frequency generator with the cell.  There are two knobs on the instrument- “ Adj ” and “Gain”.  With “ Adj ”, position of the needle on the ammeter is adjusted. The knob “Gain” is used to increase the sensitivity of the instrument.  Increase the micrometer setting till the anode current in the ammeter shows a maximum. Note down the micrometer reading. Continue to increase the micrometer setting, noting the reading at each maximum. Count any number of maxima and call it as  n . Subtract the reading at the first maximum from the reading at the last maximum. This will make the measurement accurate and we can say, d= D/(n-1).

8. OBSERVATIONS Least count of micrometer = 0.001 mm Least count of ammeter = 2 μ A 1. TABLE FOR d Measuring frequency of ultrasonic interferometer = 2MHz SN CURRENT µA ORDER OF OSCILLATION MICROMETER READING (MM) SEPARATION BETWEEN 5 OSCILLASTIONS (MM) 1 50 n 8 2.014 2 50 n+5 10.014 2.016 3 50 n+10 12.030 1.015 4 50 n+15 13.045 1.964 5 50 n+20 15.090 1.017 6 50 n+25 16.026 1.019 7 50 n+30 17.045

9. 2. TABLE FOR d SN CURRENT µA ORDER OF OSCILLATION MICR0METER READING (MM) SEPARATION BETWEEN 5 OSCILLASTIONS (MM) 1 60 n 8 1.014 2 60 n+5 9.014 2.014 3 60 n+10 11.028 1.016 4 60 n+15 12.044 1.966 5 60 n+20 14.010 1.014 6 60 n+25 15.024 2.010 7 60 n+30 17.034

10. RESULT : By ultrasonic interferometer experiment ,the ultrasonic velocity in benzene liquid is v = (1204 ± 8) m/s The compressibility of benzene is ß = (7.9 ± 0.1) N/m2

11. REFERENCES : www.Wikipedia.com https://vlab.amrita.edu www.scribd.com