Question 1 :
Assertion: The stress-strain behaviour varies from material to material. Reason: A rubber can be pulled to several times its original length and still returns to its original shape.

Question 2 :
One end of a uniform rope of length L and of weight w is attached rigidIy to a point in the roof and a weight w$_1$ is suspended from its lower. If s is the area of cross-section of the wire, the stress in the wire at a height $\displaystyle \frac{3 L}{4}$ from its lower end is:

Question 3 :
A wire whose cross-sectional area is $4\ mm^{2}$ is stretched by $0.1\ mm$ by a certain load. If a similar wire of double the area of cross-section is under the same load, then the elongation would be

Question 4 :
In Youngs expt., the distance between two slits is d/3 and the distance between the screen and the slits is 3D. The number of fringes in 1/3 m on the screen, formed by monochromatic light of wavelength $3\lambda $, will be? 

Question 5 :
Solids which break or rupture above the elastic limit are classified as:

Question 6 :
A metallic rod undergoes a strain of $0.05$%. The&#160;energy stored per unit volume is ($Y$ = $2 \times 10$ <br> $^{11}$Nm$^{-2}$):

Question 7 :
A wire of cross section $A$ is stretched horizontally between two clamps located $2l\ m$ apart. A weight $W\ kg$ is suspended from the mid-point of the wire. If the mid-point sags vertically through a distance $x &lt; 1$ the strain produced is<br>

Question 8 :
A thin rod of negligible mass and cross-sectional area $4\times 10$ <br> $^{-6}m^{2}$ , suspended vertically from one end, has a length of &#160;0.5 m at 100$^{o}$C . The rod is cooled to 0$^{o}$C .Young's modulus $=$ 10$^{11}$Nm$^{-2}$, coefficient of linear expansion $=$ 10$^{-5}$K$^{-1}$ and g $=10\ ms^{-2}$. The total energy stored in the rod is :<br/>

Question 10 :
$Y, K, $ <br> $\eta$ represent respectively the young's&#160;modulus, bulk modulus and rigidity modulus of a&#160;body. If young's modulus is twice the bulk modulus, then :

Question 11 :
Find how the volume density of the elastic deformation energy is distributed in a steel rod depending on the distance $r$ from its axis. The length of the rod is equal to $l$, the torsion angle to $\varphi$.

Question 12 :
A&#160;horizontal aluminium rod of diameter 4.8 cm projects 5.3 cm from a wall. A 1200 kg object is suspended from the&#160;end of the rod. The shear modulus of aluminium is $3.0 \, \times \, 10^{10} \, N/m^2.$ Neglecting the mass of&#160;the rod, find&#160;the&#160;vertical deflection of the end of the rod.&#160;

Question 13 :
A solid sphere of radius r made of a soft material of bulk modulus K is surrounded by a liquid in a cylindrical container. A massless piston of area a floats on the surface of the liquid, covering entire cross section of cylindrical container. When a mass m is placed on the surface of the piston to compress the liquid, the fractional decrement in the radius of the sphere, $\left(\displaystyle\frac{dr}{r}\right)$, is?