Total Questions:50 Total Time: 60 Min
Remaining:
Question:On increasing the length by 0.5 mm in a steel wire of length 2 m and area of cross-section \(2\,m{m^2}\), the force required is [Y for steel\( = 2.2 \times {10^{11}}\,N/{m^2}]\)]
\(1.1 \times {10^5}\,N\)
\(1.1 \times {10^4}\,N\)
\(1.1 \times {10^3}\,N\)
\(1.1 \times {10^2}\,N\)
Question:If Young's modulus of iron is \(2 \times {10^{11}}\,N/{m^2}\) and the interatomic spacing between two molecules is \(3 \times {10^{ - 10}}\)metre, the interatomic force constant is
60 N/m
120 N/m
30 N/m
180 N/m
Question:In CGS system, the Young's modulus of a steel wire is \(2 \times {10^{12}}\). To double the length of a wire of unit cross-section area, the force required is
\(4 \times {10^6}\)Dynes
\(2 \times {10^{12}}\)dynes
\(2 \times {10^{12}}\)newtons
\(2 \times {10^8}\)dynes
Question:The material which practically does not show elastic after effect is
Copper
Rubber
Steel
Quartz
Question:Why the spring is made up of steel in comparison of copper
Copper is more costly than steel
Copper is more elastic than steel
Steel is more elastic than copper
None of the above
Question:Steel and copper wires of same length are stretched by the same weight one after the other. Young's modulus of steel and copper are \(2 \times {10^{11}}\,N/{m^2}\) and \(1.2 \times {10^{11}}\,N/{m^2}\). The ratio of increase in length
\(\frac{2}{5}\)
\(\frac{3}{5}\)
\(\frac{5}{4}\)
\(\frac{5}{2}\)
Question:An area of cross-section of rubber string is \(2\,c{m^2}\). Its length is doubled when stretched with a linear force of \(2 \times {10^5}\)dynes. The Young's modulus of the rubber in \(dyne/c{m^2}\) will be
\(4 \times {10^5}\)
\(1 \times {10^5}\)
\(2 \times {10^5}\)
\(1 \times {10^4}\)
Question:Increase in length of a wire is 1 mm when suspended by a weight. If the same weight is suspended on a wire of double its length and double its radius, the increase in length will be
2 mm
0.5 mm
4 mm
0.25 mm
Question:The elasticity of invar
Increases with temperature rise
Decreases with temperature rise
Does not depend on temperature
Question:After effects of elasticity are maximum for
Glass
Metal
Question:In suspended type moving coil galvanometer, quartz suspension is used because
It is good conductor of electricity
Elastic after effects are negligible
Young's modulus is greater
There is no elastic limit
Question:A force of 200 N is applied at one end of a wire of length 2 m and having area of cross-section \({10^{ - 2}}\,c{m^2}\). The other end of the wire is rigidly fixed. If coefficient of linear expansion of the wire \(\alpha = 8 \times {10^{ - 6}}/^\circ C\) and Young's modulus \(Y = 2.2 \times {10^{11}}\,N/{m^2}\) and its temperature is increased by 5Ã‚Â°C, then the increase in the tension of the wire will be
4.2 N
4.4 N
2.4 N
8.8 N
Question:In steel, the Young's modulus and the strain at the breaking point are \(2 \times {10^{11}}\,N{m^{ - 2}}\) and 0.15 respectively. The stress at the breaking point for steel is therefore
\(1.33 \times {10^{11}}\,N{m^{ - 2}}\)
\(1.33 \times {10^{12}}\,N{m^{ - 2}}\)
\(7.5 \times {10^{ - 13}}\,N{m^{ - 2}}\)
\(3 \times {10^{10}}\,N{m^{ - 2}}\)
Question:Which of the following statements is correct
Hooke's law is applicable only within elastic limit
The adiabatic and isothermal elastic constants of a gas are equal
Young's modulus is dimensionless
Stress multiplied by strain is equal to the stored energy
Question:The force required to stretch a steel wire of \(1\,c{m^2}\) cross-section to 1.1 times its length would be \((Y = 2 \times {10^{11}}\,N{m^{ - 2}})\)
\(2 \times {10^6}\,N\)
\(2 \times {10^3}\,N\)
\(2 \times {10^{ - 6}}N\)
\(2 \times {10^{ - 7}}\,N\)
Question:Which one of the following substances possesses the highest elasticity
Question:Which one of the following quantities does not have the unit of force per unit area
Stress
Strain
Young's modulus of elasticity
Pressure
Question:A wire of cross-sectional area \(3\,m{m^2}\) is first stretched between two fixed points at a temperature of \(20^\circ C\). Determine the tension when the temperature falls to \(10^\circ C\). Coefficient of linear expansion \(\alpha = {10^{ - 5}}^\circ {C^{ - 1}}\) and \(Y = 2 \times {10^{11}}\,N/{m^2}\)
20 N
30 N
60 N
120 N
Question:To keep constant time, watches are fitted with balance wheel made of
Invar
Stainless steel
Tungsten
Platinum
Question:A wire is stretched by 0.01 m by a certain force F. Another wire of same material whose diameter and length are double to the original wire is stretched by the same force. Then its elongation will be
0.005 m
0.01 m
0.02 m
0.002 m
Question:The possible value of Poisson's ratio is
1
0.9
0.8
0.4
Question:The coefficient of linear expansion of brass and steel are \({\alpha _1}\) and \({\alpha _2}\). If we take a brass rod of length \({l_1}\) and steel rod of length \({l_2}\) at 0Ã‚Â°C, their difference in length \(({l_2} - {l_1})\) will remain the same at a temperature if
\({\alpha _1}{l_2} = {\alpha _2}{l_1}\)
\({\alpha _1}l_2^2 = {\alpha _2}l_1^2\)
\(\alpha _1^2{l_1} = \alpha _2^2{l_2}\)
\({\alpha _1}{l_1} = {\alpha _2}{l_2}\)
Question:A steel wire of lm long and \(1\,m{m^2}\) cross section area is hang from rigid end. When weight of 1kg is hung from it then change in length will be (given \(Y = 2 \times {10^{11}}N/{m^2})\)
0.05 mm
5 mm
Question:A load W produces an extension of 1mm in a thread of radius r. Now if the load is made 4W and radius is made 2r all other things remaining same, the extension will become
16 mm
1 mm
Question:The units of Young Ã¢â‚¬Ëœs modulus of elasticity are
\(N{m^{ - 1}}\)
N-m
\(N{m^{ - 2}}\)
\(N{\rm{ - }}{m^2}\)
Question:Two similar wires under the same load yield elongation of 0.1 mm and 0.05 mm respectively. If the area of cross- section of the first wire is \(4m{m^2},\) then the area of cross section of the second wire is
\(6m{m^2}\)
\(8m{m^2}\)
\(10\,m{m^2}\)
\(12\,m{m^2}\)
Question:A uniform plank of YoungÃ¢â‚¬â„¢s modulus Y is moved over a smooth horizontal surface by a constant horizontal force F. The area of cross section of the plank is A. The compressive strain on the plank in the direction of the force is
\(F/AY\)
\(2F/AY\)
\(\frac{1}{2}(F/AY)\)
\(3F/AY\)
Question:The mean distance between the atoms of iron is \(3 \times {10^{ - 10}}m\) and interatomic force constant for iron is \(7\,N\,/m\)The YoungÃ¢â‚¬â„¢s modulus of elasticity for iron is
\(2.33 \times {10^5}\,N/{m^2}\)
\(23.3 \times {10^{10}}\,N/{m^2}\)
\(233 \times {10^{10}}\,N/{m^2}\)
\(2.33 \times {10^{10}}\,N/{m^2}\)
Question:Two wires A and B are of same materials. Their lengths are in the ratio 1 : 2 and diameters are in the ratio 2 : 1 when stretched by force \({F_A}\) and \({F_B}\) respectively they get equal increase in their lengths. Then the ratio \({F_A}/{F_B}\) should be
1:2
1:1
2:1
8:1
Question:The breaking stress of a wire depends upon
Length of the wire
Radius of the wire
Material of the wire
Shape of the cross section
Question:The Poisson's ratio cannot have the value
0.7
0.2
0.1
0.5
Question:There is no change in the volume of a wire due to change in its length on stretching. The Poisson's ratio of the material of the wire is
0.50
0.25
Question:A material has Poisson's ratio 0.50. If a uniform rod of it suffers a longitudinal strain of \(2 \times {10^{ - 3}}\), then the percentage change in volume is
0.6
Zero
Question:Four identical rods are stretched by same force. Maximum extension is produced in
\(L = 10cm,\,\,D = 1\,mm\)
\(L = 100\,cm,\,D = \,2mm\)
\(L = 200\,cm,\,D = \,3mm\)
\(L = 300\,cm,\,D = \,4\,mm\)
Question:A uniform cube is subjected to volume compression. If each side is decreased by 1%, then bulk strain is
0.01
0.06
0.02
0.03
Question:A ball falling in a lake of depth 200 m shows 0.1% decrease in its volume at the bottom. What is the bulk modulus of the material of the ball
\(19.6 \times {10^8}\,N/{m^2}\)
\(19.6 \times {10^{ - 10}}\,N/{m^2}\)
\(19.6 \times {10^{10}}\,N/{m^2}\)
\(19.6 \times {10^{ - 8}}\,N/{m^2}\)
Question:The isothermal bulk modulus of a gas at atmospheric pressure is
\(1\,mm\)of Hg
\(13.6\,mm\)of Hg
\(1.013 \times {10^5}\,N/{m^2}\)
\(2.026 \times {10^5}N/{m^2}\)
Question:Coefficient of isothermal elasticity \({E_\theta }\) and coefficient of adiabatic elasticity \({E_\varphi }\)are related by\((\gamma = {C_p}/{C_v})\)
\({E_\theta } = \gamma \,{E_\varphi }\)
\({E_\varphi } = \gamma \,{E_\theta }\)
\({E_\theta } = \gamma /{E_\varphi }\)
\({E_\theta } = {\gamma ^2}{E_\varphi }\)
Question:If the Young's modulus of the material is 3 times its modulus of rigidity, then its volume elasticity will be
Infinity
\(2 \times {10^{10}}\,N/{m^2}\)
\(3 \times {10^{10}}\,N/{m^2}\)
Question:Modulus of rigidity of a liquid
Non zero constant
Infinite
Can not be predicted
Question:For a given material, the Young's modulus is 2.4 times that of rigidity modulus. Its Poisson's ratio is
2.4
1.2
Question:A cube of aluminium of sides 0.1 m is subjected to a shearing force of 100 N. The top face of the cube is displaced through 0.02 cm with respect to the bottom face. The shearing strain would be
0
Question:If the force constant of a wire is K, the work done in increasing the length of the wire by l is
Kl/2
Kl
\(K{l^2}/2\)
\(K{l^2}\)
Question:If the tension on a wire is removed at once, then
It will break
Its temperature will reduce
There will be no change in its temperature
Its temperature increases
Question:When strain is produced in a body within elastic limit, its internal energy
Remains constant
Decreases
Increases
Question:When shearing force is applied on a body, then the elastic potential energy is stored in it. On removing the force, this energy
Converts into kinetic energy
Converts into heat energy
Remains as potential energy
Question:A wire of length L and cross-sectional area A is made of a material of Young's modulus Y. It is stretched by an amount x. The work done is
\(\frac{{YxA}}{{2L}}\)
\(\frac{{Y{x^2}A}}{L}\)
\(\frac{{Y{x^2}A}}{{2L}}\)
\(\frac{{2Y{x^2}A}}{L}\)
Question:The elastic energy stored in a wire of Young's modulus Y is
\(Y \times \frac{{{\rm{Strai}}{{\rm{n}}^{\rm{2}}}}}{{{\rm{Volume}}}}\)
Stress \( \times \) Strain \( \times \) Volume
\(\frac{{{\rm{Stres}}{{\rm{s}}^{\rm{2}}} \times {\rm{Volume}}}}{{2Y}}\)
\(\frac{1}{2}Y \times \) Stress \( \times \) Strain \( \times \) Volume
Question:A wire of length 50 cm and cross sectional area of 1 sq. mm is extended by 1 mm. The required work will be \((Y = 2 \times {10^{10}}\,N{m^{ - 2}})\)
\(6 \times {10^{ - 2}}\,J\)
\(4 \times {10^{ - 2}}\,J\)
\(2 \times {10^{ - 2}}\,J\)
\(1 \times {10^{ - 2}}\,J\)
Question:The work per unit volume to stretch the length by 1% of a wire with cross sectional area of \(1\,m{m^2}\) will be. \([Y = 9 \times {10^{11}}\,N/{m^2}]\)
\(9 \times {10^{11}}\,J\)
\(4.5 \times {10^7}\,J\)
\(9 \times {10^7}J\)
\(4.5 \times {10^{11}}\,J\)