Chapter 8 : Mechanics of Fluids

1. Why do divers in deep sea and mountaineers at high altitude wear 'pressurized' suits ?

   Ans : The pressure is much different than sea-level atmospheric pressure.

2. How did Archimedes convince King Hero that the Crown made by the Goldsmith was not of pure gold ? Explain.

   Ans : The pure gold crown will weigh more than impure one of same size in water.

3. Water taken in the bore of a capillary laid in horizontal position does not flow but can leak away, explain. If mercury was taken instead of water, then what would happen ?

   Ans : As there is no pressure difference applied water cannot flow, but it leaks away as adhesive forces are greater than cohesive forces. For mercury it is te reverse case.

Chapter 9 : Wave motion

1. Distinguish between transverse and longitudinal waves.

2. Show that the linear, harmonic, progressive wave equation . is periodic in time.

3. Explain the change in phase of a wave reflected from a boundary.

Chapter 10 : Sound Waves

1. What are beats of sound, how are they produced ? Does a Guitarist use beats, if so how ?

2. What happens to the pitch of a horn sounded by an approaching motorist, a receding one? why?

3. Are the standing waves really waves, explain ?

4. When one tunes a radio or a T.V., which phenomenon is being used. Explain.

Chapter 11 : Temperature and Thermometers

1. Explain the concept of temperature.

2. If the temperature of an object is 50⁰C, then what will this temperature be in ⁰F & ⁰R ?

   Ans : 122 ⁰F, 40 ⁰R

Chapter 12 : Thermal Expansions of Solids, Liquids and Gases

1. Why the rails on which railway carriages move are laid with small gaps between them ?

2. Why do metal pendulum clocks fall behind the time in summer and run ahead of the time in winter?

3. The oil tankers (ships used for transporting oil) do not have their tanks completely filled oil, why ?

4. Pressure cookers used for cooking are provided with safety valves, why ?

5. A hollow metal sphere is floating on water at 0⁰C. If the temperature of water rises to q⁰C, the sphere just submerges in water. Neglect the expansion of sphere. Find expression for determining coefficient of cubical expansion of water.

   Ans : Density of water at 0⁰C ,      d = density of sphere.

6. Moon has no atmosphere, explain why is it so ?

7. Estimate the temperature at which oxygen molecules can escape from Earth. (g = 10 m/s, R_e = 6.4 10⁶ m, R = 8.3 Joule/mole ⁰K, Molecular wt. of O₂ = 32)

   Ans : T = 1.65 105 K

1. How much heat is released when steam of mass 1 gm at 100⁰C is converted to ice at 0⁰C. 'L' of condensation of steam is 540 calorie / gm, freezing of water is 80 calorie / gm and specific heat of water is 1 calorie / gm ⁰C?

   Ans : 720 calories

2. Why are burns caused by steam more severe than by water, both at 100⁰C ?

Chapter 14 : Heat Transfer

1. A piece of metal is felt to be colder than a piece of wood through both are at room temperature why ?

2. When a liquid is being heated the topmost layer is at highest temperature. State true or false giving reasons.

3. Why do the warm blooded creatures experience 'heat' and 'cold' ?
   

Chapter 15 : Thermodynamics

1. When a moving car stops all its K.E. is converted into heat. "It is possible to give the car K.E. by supplying heat to it", is the statement true ? Which law is the reason behind this possibility ? But can this possibility be realized ? Why not ?

2. When one whistles the air blown feels cooler on one's palms but when air is exhaled from the mouth it feels warmer, why ?

3. Carnot's ideal heat engine is less than 100% efficient, why ?

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Index

Questions
Bibilography

Chapter 1