## Sunday, 12 February 2017

### QUESTIONS ON THERMODYNAMICS ,OSCILLATION ANS WAVES

1.      Define Capillarity and angle of contact. Derive an expression for the ascent of a liquid in a capillary tube.
2.      Give the principle of working of venturimeter. Obtain an expression for volume of liquid flowing through he tube per second.

3.      Define the coefficients of linear expansion. Deduce relation between it and coefficient of superficial
expansion and volume expansion.
4.      Define (i) Specific heat capacity (ii) Heat capacity (iii) Molar specific heatcapacity at constant pressure and at constant volume and write their units.
5.      What is latent heat? Give its units. With the help of a suitable graph,explain the terms latent heat of
fusion and latent heat of vaporisation.
6. Show that there is always an excess pressure on the concave side of the meniscus of a liquid. Obtain  an  expression for the excess pressureinside (i) a liquid drop (ii) soap bubble (iii) air bubble inside a  liquid.
7. State and prove Bernoullis theorem. Give its limitation. Name any two application of the
principle.
8. Define terminal velocity. Obtain an expression for terminal velocity of a sphere falling through a viscous liquid. Use the formula to explain theobserved rise of air bubbles in a liquid.
9. On what factors does the rate of heat conduction in a metallic rod in the steady state depend. Write the   necessary expression and hence define the coefficient of thermal conductivity. Write its unit and dimensions.
10. Distinguish between conduction, convection and radiation.
11. Describe briefly carnot engine and obtain an expression for its efficiency.
12. Define adiabatic process. Derive an expression for work done during adiabatic process.
13. Why a gas has two principle specific heat capacities? What is the
significance of Cp – Cv and Cp/Cv where symbols have usual meaning.

14. What are the basic assumptions of kinetic theory of gases? On their basis derive an expression
for the     pressure exerted by an ideal gas.

15. What is meant by mean free path of a gas molecule? Derive an expression for it.
16. Given that P =1/3pc2 where P is the pressure, ρ is the density and c is the rms. Velocity of gas

molecules. Deduce Boyle’s law and Charles. Law of gases from it.
17.Show that for a particle in linear simple harmonic motion, the acceleration is directly proportional to its displacement of the given instant.
18. Show that for a particle in linear simple harmonic motion, the average kinetic energy over a period of oscillation, equals the average potential energy over the same period.
19.Deduce an expression for the velocity of a particle executing S.H.M when is the particle velocity (i) Maximum (ii) minimum?
20. Draw (a) displacement time graph of a particle executing SHM with phase angle φ equal to zero (b) velocity time graph and (c) acceleration time graph of the particle.
21.Show that for small oscillations the motion of a simple pendulum is simple harmonic. Derive an expression for its time period.
22.Distinguish with an illustration among free, forced and resonant oscillations.
23. In reference to a wave motion, define the terms
(i) amplitude (ii) time period
(iii) frequency (iv) angular frequency
(v) wave length and wave number.
24. Derive expressions for the kinetic and potential energies of a simple harmonic oscillator. Hence show that the total energy is conserved in
S.H.M. in which positions of the oscillator, is the energy wholly kinetic or wholly potential?
25. What are standing waves? Desire and expression for the standing waves. Also define the terms node and antinode and obtain their positions.
26. Discuss the formation of harmonics in a stretched string. Show that in case of a stretched string the first four harmonics are in the ratio 1:2:3:4,
27. Give a qualitative discussion of the different modes of vibration of an open organ pipe.
28. Describe the various modes of vibrations of a closed organ pipe.
29. What are beats? How are they produced? Briefly discuss one application
for this phenomenon.