Total Questions:50 Total Time: 60 Min
Remaining:
Question:The increase in length is l of a wire of length L by the longitudinal stress. Then the stress is proportional to
L/l
l/L
\(l \times L\)
\({l^2} \times L\)
Question:The dimensions of four wires of the same material are given below. In which wire the increase in length will be maximum when the same tension is applied
Length 100 cm, Diameter 1 mm
Length 200 cm, Diameter 2 mm
Length 300 cm, Diameter 3 mm
Length 50 cm, Diameter 0.5 mm
Question:The ratio of the lengths of two wires A and B of same material is 1 : 2 and the ratio of their diameter is 2 : 1. They are stretched by the same force, then the ratio of increase in length will be
2:1
1:4
1:8
8:1
Question:The Young's modulus of a wire of length L and radius r is Y N/\(^2\) . If the length and radius are reduced to L/2 and r/2, then its Young's modulus will be
Y/2
Y
2Y
4Y
Question:A beam of metal supported at the two ends is loaded at the centre. The depression at the centre is proportional to
\({Y^2}\)
1/Y
\(1/{Y^2}\)
Question:The diameter of a brass rod is 4 mm and Young's modulus of brass is \(9 \times {10^{10}}\,N/{m^2}\). The force required to stretch by 0.1% of its length is
\(360\,\pi N\)
36 N
\(144\pi \times {10^3}N\)
\(36\pi \times {10^5}N\)
Question:If x longitudinal strain is produced in a wire of Young's modulus y, then energy stored in the material of the wire per unit volume is
\(y{x^2}\)
\(2\,y{x^2}\)
\(\frac{1}{2}{y^2}x\)
\(\frac{1}{2}y{x^2}\)
Question:In a wire of length L, the increase in its length is l. If the length is reduced to half, the increase in its length will be
l
2l
\(\frac{l}{2}\)
None of the above
Question:The Young's modulus of 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 increase in length due to its own weight will be
\(9.6 \times {10^{ - 5}}\,m\)
\(9.6 \times {10^{ - 11}}\,m\)
\(9.6 \times {10^{ - 3}}\,m\)
9.6 m
Question:Two wires of copper having the length in the ratio 4 : 1 and their radii ratio as 1 : 4 are stretched by the same force. The ratio of longitudinal strain in the two will be
01:16
16:1
0.09
64:1:0
Question:A weight of 200 kg is suspended by vertical wire of length 600.5 cm. The area of cross-section of wire is \(1\,m{m^2}\). When the load is removed, the wire contracts by 0.5 cm. The Young's modulus of the material of wire will be
\(2.35 \times {10^{12}}\,N/{m^2}\)
\(1.35 \times {10^{10}}\,N/{m^2}\)
\(13.5 \times {10^{11}}\,N/{m^2}\)
\(23.5 \times {10^9}\,N/{m^2}\)
Question:If a load of 9 kg is suspended on a wire, the increase in length is 4.5 mm. The force constant of the wire is
\(0.49 \times {10^4}\,N/m\)
\(1.96 \times {10^4}\,N/m\)
\(4.9 \times {10^4}\,N/m\)
\(0.196 \times {10^4}\,N/m\)
Question:The ratio of diameters of two wires of same material is n : 1. The length of wires are 4 m each. On applying the same load, the increase in length of thin wire will be
\({n^2}\) Times
n times
2n times
Question:For silver, Young's modulus is \(7.25 \times {10^{10}}\,N/{m^2}\) and Bulk modulus is \(11 \times {10^{10}}\,N/{m^2}\). Its Poisson's ratio will be
1
0.5
0.39
0.25
Question:The longitudinal strain is only possible in
Gases
Fluids
Solids
Liquids
Question:If the density of the material increases, the value of Young's modulus
Increases
Decreases
First increases then decreases
First decreases then increases
Question:Young's modulus of rubber is \({10^4}\,N/{m^2}\) and area of cross-section is \(2\,c{m^2}\). If force of \(2 \times {10^5}\)dynes is applied along its length, then its initial length l becomes
3L
4L
2L
Question:Two wires of the same material have lengths in the ratio 1 : 2 and their radii are in the ratio \(1:\sqrt 2 \). If they are stretched by applying equal forces, the increase in their lengths will be in the ratio
\(2:\sqrt 2 \)
\(\sqrt 2 :2\)
01:01
01:02
Question:When a weight of 10 kg is suspended from a copper wire of length 3 metres and diameter 0.4 mm, its length increases by 2.4 cm. If the diameter of the wire is doubled, then the extension in its length will be
9.6 cm
4.8 cm
1.2 cm
0.6 cm
Question:A force of \({10^3}\) newton stretches the length of a hanging wire by 1 millimetre. The force required to stretch a wire of same material and length but having four times the diameter by 1 millimetre is
\(4 \times {10^3}\)N
\(16 \times {10^3}\)N
\(\frac{1}{4} \times {10^3}\)N
\(\frac{1}{{16}} \times {10^3}\)N
Question:Two wires Ã¢â‚¬ËœAÃ¢â‚¬â„¢ and Ã¢â‚¬ËœBÃ¢â‚¬â„¢ of the same material have radii in the ratio 2 : 1 and lengths in the ratio 4 : 1. The ratio of the normal forces required to produce the same change in the lengths of these two wires is
1:1
1:2
Question:In which case there is maximum extension in the wire, if same force is applied on each wire
L = 500 cm, d = 0.05 mm
L = 200 cm, d = 0.02 mm
L = 300 cm, d = 0.03 mm
L = 400 cm, d = 0.01 mm
Question:If a spring is extended to length l, then according to Hook's law
\(F = kl\)
\(F = \frac{k}{l}\)
\(F = {k^2}l\)
\(F = \frac{{{k^2}}}{l}\)
Question:Which of the following affects the elasticity of a substance
Hammering and annealing
Change in temperature
Impurity in substance
All of these
Question:An iron rod of length 2m and cross section area of \(50\,m{m^2}\), stretched by 0.5 mm, when a mass of 250 kg is hung from its lower end. Young's modulus of the iron rod is
\(19.6 \times {10^{10}}\,N/{m^2}\)
\(19.6 \times {10^{15}}\,N/{m^2}\)
\(19.6 \times {10^{18}}\,N/{m^2}\)
\(19.6 \times {10^{20}}\,N/{m^2}\)
Question:The length of an elastic string is a metre when the longitudinal tension is 4 N and b metre when the longitudinal tension is 5 N. The length of the string in metre when the longitudinal tension is 9 N is
\(a - b\)
\(5b - 4a\)
\(2b - \frac{1}{4}a\)
\(4a - 3b\)
Question:Stress to strain ratio is equivalent to
Modulus of elasticity
Poission's Ratio
Reyhold number
Fund number
Question:Which is correct relation
\(Y < \sigma \)
\(Y > \sigma \)
\(Y = \sigma \)
\(\sigma = + 1\)
Question:If the interatomic spacing in a steel wire is 3.0Ãƒâ€¦ and \({Y_{steel}}\)= \(20 \times {10^{10}}N/{m^2}\) then force constant is
\(6 \times {10^{ - 2}}\,N/{\AA}\)
\(6 \times {10^{ - 9}}N/{\AA}\)
\(4 \times {10^{ - 5}}\,N/{\AA}\)
\(6 \times {10^{ - 5}}N/{\AA}\)
Question:Minimum and maximum values of PoissonÃ¢â‚¬â„¢s ratio for a metal lies between
\( - \infty \) to +\(\infty \)
0 to 1
\( - \infty \,\)to 1
0 to 0.5
Question:A wire of diameter 1mm breaks under a tension of 1000 N. Another wire, of same material as that of the first one, but of diameter 2 mm breaks under a tension of
500 N
1000 N
10000 N
4000 N
Question:YoungÃ¢â‚¬â„¢s modulus of perfectly rigid body material is
Zero
Infinity
\({\rm{1}} \times {\rm{1}}{{\rm{0}}^{{\rm{10}}}}\,N/{m^2}\)
\({\rm{10}} \times {\rm{1}}{{\rm{0}}^{{\rm{10}}}}\,N/{m^2}\)
Question:A wire of length 2 m is made from \(10\;c{m^3}\) of copper. A force F is applied so that its length increases by 2 mm. Another wire of length 8 m is made from the same volume of copper. If the force F is applied to it, its length will increase by
0.8 cm
1.6 cm
2.4 cm
3.2 cm
Question:The ratio of the adiabatic to isothermal elasticities of a triatomic gas is
4/3
5/3
3/4
Question:If the volume of the given mass of a gas is increased four times, the temperature is raised from 27\(^\circ \)C to 127\(^\circ \)C. The elasticity will become
4 times
1/4 times
3 times
1/3 times
Question:The compressibility of water is \(4 \times {10^{ - 5}}\) per unit atmospheric pressure. The decrease in volume of 100 cubic centimeter of water under a pressure of 100 atmosphere will be
0.4 cc
\(4 \times {10^{ - 5}}\,cc\)
0.025 cc
0.004 cc
Question:If a rubber ball is taken at the depth of 200 m in a pool, its volume decreases by 0.1%. If the density of the water is \(1 \times {10^3}\,kg/{m^3}\) and \(g = 10\,m/{s^2}\), then the volume elasticity in \(N/{m^2}\) will be
\({10^8}\)
\(2 \times {10^8}\)
\({10^9}\)
\(2 \times {10^9}\)
Question:For a constant hydraulic stress on an object, the fractional change in the object's volume\(\left( {\frac{{\Delta V}}{V}} \right)\)and its bulk modulus (B) are related as
\(\frac{{\Delta V}}{V} \propto \frac{1}{B}\)
\(\frac{{\Delta V}}{V} \propto {B^2}\)
\(\frac{{\Delta v}}{v} \propto {B^{ - 2}}\)
\(\frac{{\Delta V}}{V} \propto B\)
Question:Modulus of rigidity of diamond is
Too less
Greater than all matters
Less than all matters
Question:The ratio of lengths of two rods A and B of same material is 1 : 2 and the ratio of their radii is 2 : 1, then the ratio of modulus of rigidity of A and B will be
4:1
Question:Which statement is true for a metal
\(Y < \eta \)
\(Y = \eta \)
\(Y > \eta \)
\(Y < 1/\eta \)
Question:A 2 m long rod of radius 1 cm which is fixed from one end is given a twist of 0.8 radians. The shear strain developed will be
0
0.01
0.02
Question:A rod of length l and radius r is joined to a rod of length l/2 and radius r/2 of same material. The free end of small rod is fixed to a rigid base and the free end of larger rod is given a twist of \(\theta ^\circ \), the twist angle at the joint will be
\(\theta /4\)
\(\theta /2\)
\(5\theta /6\)
\(8\theta /9\)
Question:Shearing stress causes change in
Length
Breadth
Shape
Volume
Question:If the potential energy of a spring is V on stretching it by 2 cm, then its potential energy when it is stretched by 10 cm will be
V/25
5V
V/5
25V
Question:The Young's modulus of a wire is Y. If the energy per unit volume is E, then the strain will be
\(\sqrt {\frac{{2E}}{Y}} \)
\(\sqrt {2EY} \)
EY
\(\frac{E}{Y}\)
Question:The ratio of Young's modulus of the material of two wires is 2 : 3. If the same stress is applied on both, then the ratio of elastic energy per unit volume will be
03:02
02:03
03:04
04:03
Question:The length of a rod is 20 cm and area of cross-section \(2\,c{m^2}\). The Young's modulus of the material of wire is \(1.4 \times {10^{11}}\,N/{m^2}\). If the rod is compressed by 5 kg-wt along its length, then increase in the energy of the rod in joules will be
\(8.57 \times {10^{ - 6}}\)
\(22.5 \times {10^{ - 4}}\)
\(9.8 \times {10^{ - 5}}\)
\(45.0 \times {10^{ - 5}}\)
Question:If a spring extends by x on loading, then the energy stored by the spring is (if T is tension in the spring and k is spring constant)
\(\frac{{{T^2}}}{{2x}}\)
\(\frac{{{T^2}}}{{2k}}\)
\(\frac{{2x}}{{{T^2}}}\)
\(\frac{{2{T^2}}}{k}\)
Question:Wires A and B are made from the same material. A has twice the diameter and three times the length of B. If the elastic limits are not reached, when each is stretched by the same tension, the ratio of energy stored in A to that in B is
2:3
3:4
3:2
6:1