19 September 2011

Properties of Matter & Sound - Unit wise Questions

                                                    Unit – I (Elasticity)

Part – A
1. Define Beam.
2. What is plane of bending?
3. What is neutral axis?
4. Define cantilever.
5. State differences between uniform and non-uniform bending.
Answer :
1) In uniform bending, every element of the beam is bent with the same radius of curvature (R).                In non-uniform bending, R is not the same for all the elements in the beam.
2) In uniform bending, the beam is elevated due to load. In non-uniform bending, the beam is depressed due to load.

Part – B
1. Calculate the work done in twisting a metal wire.
2. Derive the expression for internal bending moment of a beam.
3. Derive the expression for depression of loaded end of a cantilever.
4. Derive the expression for torque per unit twist.

Part – C
1. Describe the experiment to find the rigidity modulus of a wire using Torsional pendulum. Derive the formula used in the experiment.
2. Describe, with relevant theory, an experiment to determine the Young’s modulus of the material of a bar by uniform bending.
3. Describe, with relevant theory, an experiment to determine the Young’s modulus of the material of a bar by non-uniform bending. 

Unit – II (Surface Tension & Viscosity)

Part – A
1. Define surface tension.
2. Define adhesive and cohesive forces.
3. What is the range of molecular attraction?
4. What is the sphere of influence of the molecules?
5. Define surface energy.
6. Define angle of contact.
7. Define viscosity.
8. Define coefficient of viscosity.
9. State Stoke’s law.
10. Define terminal velocity.
11. Define streamline and turbulent flow.
12. Define Reynolds number.
13. Define critical velocity.
Part – B

1. Show that surface tension is numerically equal to the surface energy per unit area.
2. Describe a laboratory method for determining the coefficient of viscosity of a liquid at room temperature.
3. Deduce Stoke’s formula for the terminal velocity of a spherical drop falling with uniform velocity under gravity.
4. Describe an Stoke’s experiment to determine coefficient of viscosity of a highly viscous liquid.
5. Describe an experiment for comparing the viscosities of two liquids.

Part – C
1. Describe with necessary theory Quincke’s drop method of finding surface tension & angle of contact of mercury.
2. Derive Poiseuille’s formula for the rate of flow of a liquid through a capillary tube. 

Unit – III (Diffusion & Osmosis)

Part – A
1. Define diffusion.
2. Define coefficient of diffusion.
3. State diffusion of gases.
4. State Graham’s law of diffusion of gases.
5. Define osmosis.
6. Define osmotic pressure.
7. State laws of osmotic pressure.

Part – B

1. Explain what you understand by diffusion. State Fick’s law of diffusion in liquids.
2. Describe an experiment for determination of coefficient of diffusion.
3. State differences between diffusion and osmosis.

Part – C

1. How would you measure accurately the osmotic pressure of a solution by Pfeffer’s method?

Unit – IV (Gravitation)

Part – A
1. State Newton’s law of gravitation.
2. State the advantages of Boys method.
3. Define gravitational constant.

Part – B

1. State and explain Kepler’s laws of planetary motion.
2. How are the mass and density of earth found?

Part – C

1. Explain how would you determine the value of G by Boys method.
2. Obtain an expression for the period of a compound pendulum. Briefly explain the method of determining ‘g’ using compound pendulum.

Unit – V (Sound)

Part – A
1. State Doppler effect in sound.
2. What is Ultrasonic wave?
3. State the properties of ultrasonic waves.
Answer :
1. They have high energy content.
2. Just like ordinary sound waves, ultrasonic waves get reflected, refracted and absorbed.
3. They can be transmitted over large distances with no appreciable loss of energy.
4. They produce intense heating effect when passed through a substance.

Part – B
1. Describe the uses of ultrasonic waves.
2. Write a short note on Acoustics of buildings.
3. What is Doppler effect? Give four applications of the effect.
4. Explain how can the reverberation time in a hall can be adjusted?

Part – C
1. Describe the principle and production of ultrasonics by Piezo – electric generator.