LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

   B.Sc. DEGREE EXAMINATION – PHYSICS

CC 02

FIRST SEMESTER – November 2008

PH 1501 – PROPERTIES OF MATTER & ACOUSTICS

 

 

 

Date : 10-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

PART-A

 

Answer ALL questions:                                                          10 x 2 = 20 marks

 

1. State Hooke’s law of elasticity.
2. Define Poisson’s ratio. What are the theoretical limits of its value?
3. Differentiate streamlined motion from turbulent motion
4. Give two properties of a good lubricant
5. Define surface tension of a liquid Give it’s unit.
6. Calculate the excess pressure inside an air bubble of diameter 0.2 mm which is surrounded on all sides by water of surface tension 0.07 N/m
7. What are beats?
8. What is Piezo electric effect ?
9. Define reverberation time..
10. State the principle of superposition.

 

PART-B

Answer any FOUR questions:                                                4 x 7.5 = 30 marks

 

11. Calculate the bending moment for a beam of cross sectional area ‘A’, which forms part of a circle of radius ‘R’. The Young’s modulus of the material of the beam is ‘q’.
12. Describe the working of a mercury diffusion pump.
13. Describe the Jaeger’s method for determining the surface tension of a liquid.
14. Find the reflection and transmission amplitude coefficient for a transverse wave at the boundary of two strings.
15. What are ultrasonic waves?, How are they produced using a magnetostriction oscillator.

PART-C

Answer any FOUR questions:                                                4 x 12.5 = 50 marks

 

16. a). Calculate the torsional couple required to twist a wire through an angle ‘ q’

b). If a circular disc of moment of inertia ‘I’ is suspended at the end of the wire of length

‘l’, calculate the time period of oscillations and  hence the rigidity modulus of the

material of the wire.

 

 

 

 

 

17. a) Describe the Rankine’s method to determine the viscosity of a given gas.

b). Olive oil in a tall cylinder is made to flow through a horizontal capillary tube

connected to the cylinder 50 cm below the surface of the liquid. If the tube is 10 cm

long and 2mm in diameter how much oil will flow through in 20 second?, Density of

olive oil is 0.918 gm/cc ; viscosity of olive oil is 0.08 Ns/m²

18  a). Calculate the work done in increasing the radius of a spherical soap bubble from

1cm to 5 cm. Surface tension of soap solution is 0.028 N/m.

b). Describe Quincke’s method to determine the surface tension and angle of contact of

mercury.

19. a). What is Doppler effect? Derive the formula for the change in frequency (i) When the

source is moving towards the stationary observer. (ii) When the source is moving

away from stationary observer. (iii) When the observer is moving towards the

stationary source. (Iv) When the observer is moving away from the source.

b). Find the vibrating length of the wire if it vibrates at 50 Hz subjected to a tension of

1 Newton. The linear density of the wire is 1.53 x 10^-3 kg/m.

20. a). Define the absorption coefficient of sound wars for material.

b). How is it determined experimentally?

c). Give the conditions for good acoustics in an auditorium.

 

 

Go To Main page

 

 

 

 

 

 

   LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

XC 02

B.Sc. DEGREE EXAMINATION – PHYSICS

FIRST SEMESTER – April 2009

 PH 1502 / 1501 – PROPERTIES OF MATTER & ACOUSTICS

 

 

 

Date & Time: 22/04/2009 / 1:00 – 4:00   Dept. No.                                                   Max. : 100 Marks

 

 

PART A: ANSWER ALL QUESTIONS                                                      (10 x 2 = 20)           

 

• Define Poisson’s ratio.
• The Young’s modulus of a metal is 2×10¹¹N/m² and its breaking stress is 1.078×10⁹N/m². Calculate the maximum amount of energy per unit volume which can be stored in the metal when stretched.
• What is streamline motion?
• Define coefficient of viscosity. Give its SI unit.
• Give the dimension and unit of surface tension.
• Define the term angle of contact.
• State the principle of superposition of waves.
• What are beats?
• Define reverberation time.
• Give the principle of magnetostriction effect.

 

PART B: ANSWER ANY 4 QUESTIONS                                                          (4 x 7.5 = 30)

 

• (Show that.) Obtain a relation between the three elastic modulii.
• Discuss the working of a McLeod gauge.
• (a) A liquid drop of radius R breaks up into 64 small drops.  Calculate the change in energy.
  (b) An air bubble of radius 0.1mm is situated just below the surface of water.  Calculate the

excess pressure inside the air bubble. (Surface tension of water = 7.2 x 10^-2N/m).

• (a) Discuss the vibration of the air column in an open organ pipe.
  (b) An open organ pipe sounds the fundamental note of frequency 200Hz.  Find the length of the

pipe (velocity of sound in air is 350m/s).

• What is piezo-electric effect? Explain how this method is employed to produce ultrasonic waves. Mention any two applications of ultrasonics.

 

PART C: ANSWER ANY 4 QUESTIONS                                                           (4 x 12.5 = 50)

 

• (a) Derive an expression for the couple per unit twist due to torsional oscillations.

(b) Calculate the work done in twisting a steel wire of radius 10^-3m and length 0.25m through an

angle 45˚. Given rigidity modulus = 8×10¹⁰N/m².

 

• (a) Obtain Stoke’s law for the motion of a body in a viscous medium from dimensional

considerations.

 

 

(b) Find the limiting velocity of a rain drop.  (Given diameter of the drop = 10^-3m, density of air

relative to water = 1.3 x10^-3, coefficient of viscosity of air = 1.8 x 10^-5SI units and density of

water 10³kg/m³).

 

• a) Show that the vapor pressure on the curved surface of a liquid differs from that on the

plane surface of the same liquid by.
(b)  Calculate the difference in vapor pressure of water for a plane surface and for a drop of

radius 0.2mm.  Density of water vapor = 6 x 10^-4g/cm³ and surface tension of water = 70

dynes/cm.

 

• Explain Doppler effect. Derive an expression for the change in frequency of a note when
  • observer is at rest and source in motion
  • observer in motion and source is at rest and
  • observer and source in motion.

and Discuss the effect of wind.

 

• (a) Write down Sabine’s reverberation formula and explain the symbols.
  (b) Derive an expression to calculate the absorption coefficient.
  (c) The volume of a room is 600m³. The wall area of the room is 220m², the floor area is 120

m², and the ceiling area is 120 m².  The average sound absorption coefficient,

(i) for the walls is 0.03:

(ii) for the ceiling is 0.8 and

(iii) for the floor is 0.06.  Calculate the average sound absorption coefficient and reverberation

time.

 

 

Go To Main page

 

 

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

   B.Sc. DEGREE EXAMINATION – PHYSICS

FIRST SEMESTER – NOVEMBER 2010

PH 1502/PH 1501 – PROPERTIES OF MATTER & ACOUSTICS

 

 

 

Date : 10-11-10                     Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

PART – A

 

Answer ALL questions                                                                                            (10 x 2 =20 marks)

 

1. Define Bulk modulus of elasticity with mathematical expression.
2. A load of 2 kg weight produces an extension of 1 mm in a wire of length 3 meters and 1 mm in diameter. Calculate the young’s modulus of the wire. (g = 9.8 m / s²)
3. Define stream line and turbulent motion of liquid.
4. Define co-efficient of viscosity. Give its S.I unit.
5. Define surface tension of a liquid. What are its dimensions and unit?
6. What is adhesion and molecular range in surface tension?
7. Explain the term wave motion. Distinguish between transverse and longitudinal wave motion.
8. What are beats?
9. What is piezoelectric effect?
10. Define reverberation.

PART – B

 

Answer any FOUR questions                                                                                     (4 x 7.5 =30 marks)

 

11. Derive the expression for the period of oscillation a torsion pendulum.                     (7.5)
12. Describe and explain the working of the rotatary oil pump.         (7.5)

 

13. a) Describe Jaeger’s method for determining the surface tension of a liquid.         (4.5)

 

1. b) Calculate the excess of pressure between the inside and outside of a soap bubble of

radius 1 cm surface tension of soap solution is 3.2 x 10^-2N /m.                                          (3)

 

14. a) Discuss the vibration of the air column in a closed organ pipe. (4)

 

50. b) Two open organ pipes of lengths 50 cm and 50.5 cm produce 3 beats / second.

Calculate the velocity of sound in air.                                                                      (3.5)

 

15. a) Write any two properties of ultrasonic waves. (2)

 

5. b) Explain how ultrasonics is produced in a magnetostriction oscillator.         (5.5)

 

PART – C

 

Answer any FOUR questions                                                                                                 (4×12.5=50 marks)

 

16. a) Describe Koenig’s method for the determination of young’s modulus of a beam. (9.5)

 

1. b) Find the amount of work done in twisting a steel wire of radius 10 ^-3 m and of length 0.25 m

through an angle of 45⁰. Given G for steel = 8 x 10¹⁰ Nm^-2.                                                        (3)

 

17. a) Derive Poiseuille’s formula for the rate of flow of a liquid through a capillary tube. (9.5)

 

1. b) Calculate the mass of water flowing in 10 minutes through a tube 0.001 m diameter and 0.4

m long if there is a constant pressure head of 0.2 m of water. The co-efficient of viscosity of

water is 0.00082 Nsm^-2                                                                                                                     (3)

 

18. a) Describe Quincke’s method to determine the surface tension and angle of contact of

mercury.                                                                                                                                           (9.5)

 

1. b) There is a minute circular hole at the bottom of a small hollow vessel. The vessel has to be

immersed in water to a depth of 0.4 m, before any water penetrates inside. Find the radius

of the holes, if the surface tension and density of water be 73 x 10^-3 Nm^-1 and 1000 kgm^-3

respectively.                                                                                                                                        (3)

 

19. a) Explain Doppler Effect.  (3)

 

1. b) Derive an expression for the change in frequency.

(i) Observer is at rest and source in motion (ii) Observer in motion and source is at rest and

(iii) Observer and source in motion and write the limitations of Doppler effect.                  (9.5)

 

20. a) Derive the Sabine’s formula for reverberation time.         (8)

 

4. b) Write a short note on noise reduction.                    (4.5)

 

 

Go To Main page

 

 

 

 

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – PHYSICS

FIRST SEMESTER – APRIL 2012

PH 1502/PH 1501/1500 – PROPERTIES OF MATTER & ACOUSTICS

 

 

 

Date : 28-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

               PART – A

Answer ALL questions:                                                                                                        (10×2=20 Marks)   

 

1. State Hook’s law.
2. Explain the term neutral axis in bending of a beam.
3. Distinguish streamline and turbulent motion of a liquid .
4. Explain the principle of Pirani Gauge.
5. Write down the unit and dimension of surface tension .
6. What happens when a capillary tube is dipped in water and mercury?
7. Mention any two conditions for causing interference in sound waves.
8. Find the wavelength of sound produced by a tuning fork of frequency 400Hz. Given velocity of sound wave is 320m/sec.
9. Define reverberation time

10. A hall of volume 5500m³ is found to have a reverberation time of 2.3 sec. The sound absorbing surface of the hall has an area of 750m². Calculate the average absorption coefficient.

 

PART – B

 

      Answer any FOUR questions:                                                                        (4×7.5=30 Marks)

 

11. a) Derive the expression for the period of oscillation of a cantilever. (3+4.5)
12. b) Describe with necessary theory, the oscillation method to determine the Young’s

modulus of a cantilever. (Assume mass of the cantilever is negligible).

12. a) Discuss briefly the method of comparing coefficient of viscosities of two liquids using

Ostwald viscometer.                                                                                                                        (5+2.5)

1. b) What are the advantages of Ostwald viscometer ?
2. a) Explain how surface tension is accounted for using molecular theory. (4+3.5)
3. b) Explain the variation of surface tension with temperature.
4. Distinguish between progressive and stationary wave.
5. Write a note on any five applications of ultrasonics.

 

 

 

 

PART – C

 

      Answer any FOUR questions:                                                                       (4×12.5=50 Marks)

    

16. a) Describe Koenig’s method for the determination of Young’s modulus of a beam. (9+3.5)
17. b) A uniform metal disc of diameter 0.1m and mass 1.2kg is fixed to the lower end of a torsion wire of

length 1m and diameter 1.4×10^-3m. Calculate the rigidity modulus of  the material of the wire,

if  period of oscillation is 2sec.

17. a) Explain the principle and working of a Knudsen gauge.             (9+3.5)
18. b) Calculate the mass of water flowing 10 minutes through a tube of 0.001m diameter and 0.4m long,

if there is a constant pressure head of 0.2m of water. Coefficient of water is 0.00082 Nsm^-2.

18. a) Describe the Jaeger’s method for the determination of surface tension of a liquid. (8+4.5)
19. b) Discuss the advantages and disadvantages of the method.
20. a) What is Doppler effect? (2.5+10)
21. b) Derive an expression for the change in frequency when i) observer is at rest and source is in

motion and ii) observer is in motion and source is at rest.

20. Discuss the salient points associated with acoustics of an auditorium.

 

 

Go To Main page

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – PHYSICS

FIRST SEMESTER – NOVEMBER 2012

PH 1503/1502/1501/1500 – PROPERTIES OF MATTER & ACOUSTICS

 

 

Date : 08/11/2012             Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

PART – A

 Answer ALL questions:                                                                                               [ 10 x 2 = 20]

1. Explain the shess – shrain graph law.
2. State the difference between uniform and non-uniform bending.
3. Define coefficient of viscosity of a liquid and give its dimension.
4. How does temperature affect viscosity?
5. How is the surface energy of a liquid related to its surface tension?
6. Give two examples where theory of surface tension is in action.
7. Show the standing wave pattern for the first harmonic of an open ended organ pipe diagrammatically.
8. What is the difference between transverse and longitudinal waves? Are sound waves in air transverse or longitudinal?
9. Give the principle of magnetostriction method of producing ultrasonics.
10. What are the factors affecting the acoustic quality of a building?

PART – B

Answer any FOUR questions:                                                                                          [ 4 x 7.5 = 30]

11. Compare the loads required to produce equal depressions for two beams made of the same material and having the same lengths and weight with only difference being one has circular cross section while the other has square cross section.
12. Describe the Quinke’s method of determining the surface tension of Mercury.
13. Write a note on (a) Rotary oil pump and (b) Mercury diffusion pump.
14. Discuss the phenomenon of sharpness of resonance and show how it depends upon the damping factor.
15. Derive Sabine’s formula for reverberation time.

 

PART – C

Answer any FOUR questions.                                                                                    [ 4 x 12.5 = 50]

16. a) Derive the expression for the depression of the loaded end of a cantilever.
17. b) Hence derive the expression for the depression of a beam subjected to non – uniform bending.

( 7+5.5 )

17. a) Derive the expression for coefficient of viscosity by Poiseuille’s flow using method of

dimensions.

1. b) How is the formula used to compare the coefficients of viscosity of two liquids using Ostwald

Viscometer?

( 7+5.5 )

18. a) Explain with theory the Jaegar’s method of determining the surface tension of a liquid.
19. b) Write a note on variation of surface tension of a liquid with temperature.

( 9+3.5 )

19. a) What is Doppler effect?
20. b) Derive expressions for the apparent frequency of a note when

(i) Observer is at rest and source is in motion (ii) observer is in motion and source is at rest

and (iii) observer and source are in motion.

( 2+10.5 )

20. a) What is Piezo electric effect?
21. b) Describe the method of producing ultrasonics using Piezo electric effect.
22. c) List any three properties of ultrasonics.

( 2+7.5+3 )

 

Go To Main Page

 

Go To Main Page