Elasticity
1)what is stress and strain ?
2)which is more fundamental between stress and strain ?
3)Define Young’s modulus and Bulk modulus ? what is their unit ?
5) State Hook’s law . Define the modulus of rigidity ?
6)Define poisson’s ratio .What are its limiting values ?
7)Discuss whether Poisson’s ratio is an elastic modulus or not ?
8)What do you mean by the force constant of a spring ? which property of the spring is expressed by it ?
9)What is elastic fatigue ?
10)Which is more elastic between steel and rubber ?
11)Spring are usually made of steel but not of copper why ?
12)Explain why the temperature of a wire under tension will changed if it snaps suddenly ?
13)The Poisson’s ratio of a wire is . Shoe that if e is the longitudinal strain due to an applied force , the volume
strain will be e(1 - 2 ) .
OR
A metallic wire is elongated by an external force . If the volume of the wire remain unchanged , than prove that
the value of poisson’s ratio for the metallic wire is ½.
14)What do you mean by elastic potential energy ? Show that the elastic potential energy per unit volume of a
wire stretched longitudinally = ½ x stress x strain .
OR
A wire of initial length L and area of cross section A , having Young’s modulus Y of its material , is stretched to be
elongated by an small amount x . Prove that work done in stretching the wire is
YAx2/2L .
EXPANSION OF SOLID , LIQUIDE AND GAS
1) Establish relation among the three coefficient of expansion of solid .
2) Define coefficient of linear expansion of solid . Show that the coefficient of linear expansion dose not
depends on the unit of length but depends on the unit of temperature .
3) Establish an equation showing the variation of density of solid with the change in temperature.
4) What is thermal stress ? Obtain the expression for thermal stress .
5) Define coefficient of real and apparent expansion of liquid .Establish a relation between them.
6) Show how density of a liquid varies with temperature ?
7) What is anomalous expansion of water ? Effect of anomalous expansion of water on Marine life .
8) An iron rod is fitted along the diameter of a circular iron ring. Explain whether the ring remains circular or
not , when the system is heated .
9) A platinum wire can easily be sealed to a glass bulb while a copper wire cannot , why ?
10) The different in length of two rods , made up of different materials , remains constant at all temperatures
. Show that their length at 0°C are inversely proportional to their coefficient of linear expansion.
11) Define volume coefficient and pressure coefficient of a gas .Prove that in case of an ideal gas these two
coefficients are equal in magnitude.
12) What do you mean by absolute scale of temperature ? How is the concept of this scale obtained from
Charles’ law ? Why it is called absolute ? Establish the equation for an ideal gas from Boyle’s law and
Charles’ law .
*** For numerical see examples of your book (only previous years question )