Question 2 :
Assertion: Strain is a unitless quantity. Reason: Strain is equivalent to force

Question 3 :
If longitudinal strain for a wire is $0.03$ and its poisson ratio is $0.5$, then its lateral strain is

Question 4 :
A compressive force is applied to a uniform rod of rectangular cross-section so that its length decreases by $1\%$. If the Poisson’s ratio for the material of the rod be $0.2$, which of the following statements is correct ? The volume approximately .....”

Question 5 :
There are two wires of same material. their radii and lengths are both in the ratio 1:2. if the extensions produced are equal, what is the ratio of the loads?

Question 7 :
The force required to double the length of the steel wire of area of cross section $5\times 10^{-5}m^{2}\quad (Y=20\times 10^{10}Pa)$ in $N$ is:

Question 8 :
The Young's modulus of the material of the wire of length $L$ and radius $r$ is $Y{ N }/{ { m }^{ 2 } }$. If the length is reduced to ${ L }/{ 2 }$ and radius ${ r }/{ 2 }$, the Young's modulus will be:

Question 11 :
Three wires P,Q and R the same materials and length have radii $0.12cm,0.2cm$ and $0.3cm$ respectively. Which wire has the highest value of Young's modules of elasticity ?

Question 12 :
The Young's modulus a rubber string 8 cm long and density 1.5 kg/ $m^{3}$ is $5\times 10^{8}N/m^{2}$, is suspended on the ceiling in a room. The increases in length due to its own weigth will be 

Question 13 :
A load of $4.0\ kg$ is suspended from a ceiling through a steel wire of length $20\ m$ and radius $2.0\ mm$. It is found that the length of the wire increases by $0.031\ mm$ as equilibrium is achieved. If $g=3.1\ x\ \pi\ ms^{-2}$, the value of young's modulus in $Nm^{-2}$ is

Question 14 :
A uniform metal rod of $2mm$ <br> $^{2}$ cross section is&#160;heated from 0$^{o}$C to 20$^{o}$C. The coefficient of linear&#160;expansion of the rod is 12 x 10$^{-6/0}$C. Its Young's&#160;modulus of elasticity is 10$^{11}$ N/m$^{2}$. The energy&#160;stored per unit volume of the rod is :

Question 15 :
A thin 1 m long rod has a radius of 5 mm.1 A force of 50 $\pi kN$ is applied at one end to determine its Young's modulus. Assume that the force is exactly known. If the least count in the measurement of all lengths is 0.01 mm, which of the following statements is false ? <br>

Question 16 :
When temperature of a gas is $20^{\circ}C$ and pressure is changed from $p_{1} = 1.01\times 10^{5} Pa$ to $p_{2} = 1.165\times 10^{5} Pa$, the volume changes by $10\%$. The bulk modulus is

Question 17 :
If a rubber ball is taken at the depth of $200m$ in a pool, its voulme decreases by $0.1\%$. If the density of the water is $1\times 10^3kg/m^3$ and $g=10m/s^2$, then the volume elasticity in $N/m^2$ will be

Question 18 :
A $5$ metre long wire is fixed to the ceiling. A weight of $10kg$ is hung at the lower end and is $1$metre above the floor. The wire was elongated by $1mm$. The energy stored in the wire due to stretched is

Question 19 :
In performing an experiment to determine the Young's modulus Y of steel, a student can record the following values:<br>length of wire l$=(\ell_{0}\pm\Delta$l$){m}$<br>diameter of wire ${d}=({d}_{0}\pm\Delta {d})$ mm<br>force applied to wire ${F}$=$({F}_{0}\pm\Delta {F}){N}$<br>extension of wire ${e}=({e}_{0}\neq\Delta {e})$ mm<br>In order to obtain more reliable value for Y, the followlng three techniques are suggested. <br>Technique (i) A shorter wire ls to be used.<br>Technique (ii) The diameter shall be measured at several places with a micrometer screw gauge.<br>Technique (iii) Two wires are made irom the same ntaterial and of same length. One is loaded at a fixed weight and acts as a reference for the extension of the other which is load- tested<br>Which of the above techniques is/are useful?<br>

Question 20 :
A uniform pressure p is exerted on all sides of a solid cube at temperature ${t^0}C$. By what amount should the temperature of the cube be raised in order to bring its volume back to the value it had before the pressure was applied? The coefficient of volume expansion of the cube y and the bulk modulus is B.

Question 21 :
The Young's modulus of a material is $2\times { 10 }^{ 11 }N/{ m }^{ 2 }$ and its elastic limit is $1.8\times { 10 }^{ 8 }N/{ m }^{ 2 }$. For a wire of $1m$ length of this material, the maximum elongation achievable is

Question 22 :
The length of a metal is $l_1$ when the tension in it is $T_1$ and is $l_2$ when the tension is $T_2$. The original length of the wire is&#160; :<br/>

Question 23 :
The length of a metal wire is $l_{1}$ when the tension in it is $T_{1}$ and is $l_{2}$ when the tension is $T_{2}$. The natural length of wire is

Question 24 :
A heavy uniform rod is hanging vertically form a fixed support. It is stretched by its won weight. The diameter of the rod is&#160;

Question 25 :
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?

Question 26 :
The density of water at the surface of the ocean is $\rho$ and atmospheric pressure is ${P}_{0}$. If the bulk modulus of water is $K$, what is the density of ocean water at a depth where the pressure is then$n{P}_{0}$?

Question 27 :
A uniformly tapering conical wire is made from a material of Young's modulus $Y$ and has a normal, unextended length $L$. The radii, at the upper and lower ends of this conical wire, have values $R$ and $3R$, respectively. The upper end of the wire is fixed to a rigid support and a mass $M$ is suspended from its lower end. The equilibrium extended length, of this wire, would equal to:<br/>

Question 28 :
In a Young's double slit experiment with sodium light, slits are 0.589 m apart. The angular separation of the maximum from the central maximum will be (given $\lambda =589$nm,):

Question 29 :
A thick uniform bar lies on a frictionless horizontal surface and is free to move in any way on the surface. Its, mass is $0.16kg$ and length is $1.7m$. Two particles each of mass $0.08kg$ are movingon the same surface and twards the bar in the direction perpendicular to the bar, one with a velocity of $10m{s}^{-1}$ and other with velocity $6m{s}^{-1}$. If collision between particles and bar is completely inelastic, both particles strike with the bar simultaneously. The velocity of centre of mass after collision is

Question 30 :
A particle of rest mass ${m}_{0}$ moves with a speed $\cfrac { C }{ 2 } $ its total energy and kinetic energy are:

Question 31 :
The $P.E.$ and $K.E.$ of a helicopter flying horizontally at a height $400\ m$ are in the ratio $5:2$. The velocity of helicopter is:

Question 32 :
Given $\overline { a } + \overline { b } + \vec { c } + \overline { d } = 0$ , which of the following statements is/are not a correct statement?

Question 33 :
In $CH_{4}$ molecule, there are four $C-H$ bonds. If two adjacent bonds are in $\hat{i}+\hat{j}+\hat{k}$ and $\hat{i}-\hat{j}-\hat{k}$ direction, then find the angle between these bonds.