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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
As shown in figure, by combining together copper and steel wires of same length and same diameter, a force F is applied at one of their end. The combined length is increased by 2 cm. The wires will have A. Same stress and same strainB. Different stress and different strainC. Different stress and same strainD. Same stress and different strain |
| Answer» Correct Answer - D | |
| 52. |
A student plots a graph from hs readings on the determination of Young modulus of a metal wire but forgets to put the labels figure. The quantities on X and Y axes may be respectively A. Weight hung and length increasedB. Stress applied and length increasedC. stress applied and strain developD. length increased and the weight hung |
| Answer» Correct Answer - A::B::C::D | |
| 53. |
Assertion : Sterss is the internal force per unit area of a body. Reason : Rubber is less elastic than steel. |
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Answer» Correct Answer - C Stress is the internal force per unit area of a body. If the same food is applied to the rubber and steel, then strain in rubber is more. It means the rubber is less elastic than steel. |
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| 54. |
The torque required to produce a unit twist in a solide bar of length `L` and radius `r` isA. `tau_(1) = tau_(2)`B. `tau_(1) lt tau_(2)`C. `tau_(1) gt tau_(2)`D. `1 & 2` are correct |
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Answer» Correct Answer - C `tau_("hollow") gt tau_("solid"), tau = (pi eta r^(4) Phi)/(2l)` |
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| 55. |
A wire suspended vertically from one of itsends is strached by attached a weight of `200 N` to the lower end . The weight streches the wire by `1 mm` . Then the elastic energy stored in the wire isA. `0.2J`B. `10J`C. `20J`D. `0.1J` |
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Answer» Correct Answer - D Elastic energy `= (1)/(2) F xx e` |
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| 56. |
A material has normal density `rho` and bulk modulus `K`. The increase in the density of the material when it is subjected to an external pressure `P` from all sides is |
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Answer» `K = (P)/((dV)/(V)) rArr (dV)/(V) = (P)/(K)` and `rho = (M)/(V)` `rho + Delta rho = (M)/(-Delta V) rArr rho = (M)/(V-Delta V) - (M)/(V)` `Delta rho = (M)/(V) [(1)/(1-(DeltaV)/(V))-1] rArr Delta rho = (M)/(V) [(1)/(1-(P)/(K))-1]` `Delta rho = (M)/(V) [(K)/(K-P)-1] rArr Delta rho = (M)/(V) [(K-K+P)/(K-P)]` `Delta rho = rho ((P)/(K-P))`. |
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| 57. |
A material has normal density `rho` and bulk modulus `K`. The increase in the density of the material when it is subjected to an external pressure `P` from all sides isA. `(p)/(rho K)`B. `(KP)/(rho)`C. `(P rho)/(K)`D. `(K rho)/(P)` |
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Answer» Correct Answer - C `K = (p)/((Delta rho)/(rho))` |
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| 58. |
As shown in adjacent figure if a load of mass `(m)` is attached at lower end of wire. Then find the displacement of the points `B,C` and `D` are as shwon in figure. (i) elongation of first wire `e_(1) = ((mg)l_(1))/(AY_(1))` (ii) elongation of `2nd` wire `e_(2) = ((mg)l_(2))/(AY_(2)) + ((mg)l_(1))/(AY_(1))` (iii) elongation of `3rd` wire `e_(3) = ((mg) l_(3))/(AY_(3)) + ((mg)l_(2))/(AY_(2)) + ((mg) l_(1))/(AY_(1))` A. (i) is correctB. (i)&(ii) is correctC. (iii) is correctD. All are correct. |
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Answer» Correct Answer - D displacement of `B` is `e_(1)`, displacement of `C` is `e_(1) + e_(2)` displacement of `D` is `e_(1) + e_(2) + e_(3)` |
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| 59. |
A block of mass `1 Kg` is fastened to one each of a wire of cross-sectional area of `2mm^(2)` and is rotated in verticle circle of radius `20cm`. The speed of the block at the bottom of the circle is `3.5ms^(-1)`. The elongation of the wire when the block is at top of the circleA. `0.6125xx10^(-5)m`B. `0.6125xx10^(-4)m`C. `0.6125xx10^(-3)m`D. `0.6125xx10^(-2)m` |
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Answer» Correct Answer - A (i) Tension at the bottom of the circle, `T = (mv^(2))/(r) + mg, e = (Fl)/(AY)` (ii) Tension at the top of the circle, `T` = Tension at the bottom `-6mg` The increment in lengh `e = (Fl)/(AY)` |
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| 60. |
Which one of the following is the property of an ionic compound?(a) High melting and boiling points(b) Low melting and boiling points(c) Weak inter-atomic forces(d) Non conductors of electricity |
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Answer» The correct choice is (a) High melting and boiling points For explanation I would say: Ionic compounds are very strong in nature. They require a lot of energy to break them. Therefore they have high melting and boiling points. |
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| 61. |
When do ionic compounds conduct electricity?(a) In gaseous state(b) In solid state(c) When dissolved in water(d) They never conduct |
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Answer» The correct choice is (c) When dissolved in water For explanation: Ionic compounds can conduct electricity only if their ions are free to move. Hence they behave as conductors when they are dissolved in water. |
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| 62. |
A `20kg` load is suspended from the lower end of a wire `10cm` long and `1mm^(2)` in cross-sectional area. The upper half of the wire is made of iron and the lower half with aluminium. The total elongation in the wire is `(Y_("iron") = 20xx10^(10) N//m^(2), Y_(Al) = 7xx10^(10) N//m^(2))`A. `18.9xx10^(-3)m`B. `17.8xx10^(-3)m`C. `1.78xx10^(-3)m`D. `1.89xx10^(-4)m` |
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Answer» Correct Answer - D `e = e_(1) + e_(2), e = (Fl)/(AY), (e_(1))/(e_(2)) = (Y_(2))/(Y_(1))` |
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| 63. |
A spherical ball of volume `1000 cm^(3)` is subjected to a pressure of `10` atomosphere. The change in volume is `10^(-2)cm^(-3)`. IF the ball is made of iron find its bulk modulus. (Atmospheric pressure `= 1xx10^(5) Nm^(-2)`)A. `1xx10^(11) N//m^(2)`B. `2xx10^(11) N//m^(2)`C. `3xx10^(11) N//m^(2)`D. `4xx10^(11) N//m^(2)` |
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Answer» Correct Answer - A `K = (P)/(-(DeltaV)/(V))` |
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| 64. |
A steel wire of diameter 2 mm has a breaking strength of `4xx10^(5)`N. What is the breaking strength of similar steel wire of diameter `1.5 mm` ?A. `2.3xx10^(5)N`B. `2.6xx10^(5)N`C. `3xx10^(5)N`D. `1.5xx10^(5)N` |
| Answer» Correct Answer - A | |
| 65. |
Which of the following covalent compounds conduct electricity?(a) Silica(b) Graphite(c) Diamond(d) Hydrogen chloride |
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Answer» Right choice is (b) Graphite The explanation: Graphite is made up of carbon layer that can slide over each other. Like metals, the electrons are free to move. Whereas, the rest of the compounds are made up of carbon atoms held together tightly. Therefore, graphite is the covalent compound that conducts electricity. |
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| 66. |
The length of a metal wire is `10cm` when the tension in it is `20N` and `12cm` when the tension is `40N`. Then natural length of the wire is in `cm`A. `6`B. `4`C. `8`D. `9` |
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Answer» Correct Answer - C Stress `= Y` strain |
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| 67. |
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)`. Then natural length of the wire is |
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Answer» Correct Answer - `(T_(2)l_(1)-T_(1)l_(2))/(T_(2)-T_(1))` Hint : `Deltal_(1)=l_(1)-l,Deltal_(2)=l_(2)-l` |
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| 68. |
Defind Poisson ration. |
| Answer» `"Poisson ratio"=("lateral strain")/("longitudinal strain")` | |
| 69. |
A metal cube of side length `8.0cm` has its upper surface displacement with respect to the bottom by `0.10mm` when a tangential force of `4xx10^(9)N` is applied at the top with bottom surface fixed. The rigidity modulus of the material of the cube isA. `4xx10^(14) N//m^(2)`B. `5xx10^(14) N//m^(2)`C. `8xx10^(14) N//m^(2)`D. `1xx10^(14) N//m^(2)` |
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Answer» Correct Answer - B `eta = (FL)/(Al), A = L^(2), eta = (FL)/(L^(2) l) = (F)/(Ll)` |
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| 70. |
A steel wire can support a maximum load of W before reaching its elastic limit. How much load can another wire, made out of identical steel, but with a radius one half the radius of the first wire, support before reaching its elastic limit?A. WB. `(W)/(4)`C. `(W)/(4)`D. `4W` |
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Answer» Correct Answer - C Breaking force = Breaking stress `xx` Area of cross section . for given material of the wire, breaking stree is constant . `therefore (F_(1))/(A_(1)) =(F_(2))/(A_(2))` `F_(2) = F_(1) ((A_(2))/(A_(1))) = F_(1)((A_(1)//4)/(A_(1))) = (F_(1))/(4) = (W)/(4)" "(because r_(2) = r_(1//2))` |
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| 71. |
A copper wire and an aluminium wire has lenghts in the ratio `3:2` diameter in the ratio `2:3` and froce applied in the ratio `4:5` find the ratio of the increase in length of the two wires `TY_(AT) = 7xx10^(10) N//m^(2), Y_(Cu) = 11xx10^(10) N//m^(2)`A. `110,89`B. `180:110`C. `189:110`D. `80:11` |
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Answer» Correct Answer - C `Y = (Fl)/(Ae), (e_(1))/(e_(2)) = (F_(1) l_(1) r_(2)^(2) Y_(2))/(F_(2) l_(2) r_(1)^(2) Y_(1))` |
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| 72. |
Braking froce per unit area of cross section of a wire is calledA. yield pointB. tensile stressC. ductilityD. breaking stress |
| Answer» Correct Answer - D | |
| 73. |
Which one of the following statements is correct? In the case ofA. shearing stress there is charge in volume.B. Â hydraulic stress there is no change in shape.C. shearing stress there is no change in shape.D. Â hydraulic stress there is no change in volume. |
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Answer» Correct Answer - B In case of shearing stress there is a change in shape without any change in volume. In case of hydraulic stress there is a change in volume without any change is shape. |
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| 74. |
In the question rumber 66, for what value of `theta`, shearing stress is maximum?A. `0^(@)`B. `30^(@)`C. `45^(@)`D. `90^(@)` |
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Answer» Correct Answer - C Shearing stress `=(F sin 2theta)/(2A)` Shearing stress is maximum when `sin 2theta =1` `or Sin 2theta = sin 90^(@) or 2theta = 90^(@)` ` or theta = 45^(@)` |
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| 75. |
A unifrom rod is fixed at one end to a rigid support, its temperture is gradually increased the representaion of graph strain `(e)` versus increment in temperature `Delta theta` is A. `d`B. `a`C. `C`D. `b` |
| Answer» Correct Answer - B | |
| 76. |
Which of the following stress versus strain curve representes cast iron?A. B. C. D. |
| Answer» Correct Answer - B | |
| 77. |
In the above graph, point `B` indicatesA. Breaking pointB. Limiting PoointC. Yield pointD. Elastic limit |
| Answer» Correct Answer - C | |
| 78. |
STATEMENT - 1 : When a rod lying freely is heated, no thermal stress is developed in it. and STATEMENT - 2 : On heating, the length of the rod increase.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1C. Statement-1 is True, Statement-2 is FalseD. Statement-1 is False, Statement-2 is True |
| Answer» Correct Answer - B | |
| 79. |
Two wires of same material and length but diameters in the ratio `1:2` are streached by the same force, the elastic potential energy per unit volume for the two wires then strechted by the same force will be in the ratioA. `16:1`B. `1:1`C. `1:4`D. `4:1` |
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Answer» Correct Answer - A `(E)/(V) = (1)/(2) (("stres")^(2))/(Y) = (1)/(2) (F^(2))/(A^(2) Y^(2)), (E)/(V) alpha (1)/(r^(4))` |
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| 80. |
The ratio of diameters of two wires of same material is `n:1`. The length of each wire is `4 m`. On applying the same load, the increases in the length of the thin wire will be `(n gt 1)`A. `n^(2)` tiemsB. `n` timesC. `2n` timesD. `(2n + 1)` times |
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Answer» Correct Answer - A `e = (Fl)/(pi r^(2)Y), F alpha r^(2)` |
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| 81. |
A copper wire `2m` long is stretched by `1mm`. If the energy strored in the stretched wire is converted into heat, then calculate the rise in temperature of the wire. |
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Answer» `m s Delta t = (1)/(2) Y ("strain")^(2) xx (m)/(p)` `Delta t = (1)/(2) xx (Y)/(s rho) xx ((e)/(l))^(2)` `Delta t = (1)/(2) xx (12.5xx10^(10))/(9xx10^(3)xx385) xx [(1)/(1000xx2)]^(2) = 0.0045^(@)C` So the rise in tempertuare of the wire is `0.0045^(@)C` |
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| 82. |
 For an ideal iquidA. bulk modulus is infinite and shear modulus is zero.B.  bulk modulus is zero and shear modulus is inifinite.C. bulk moduius is infinite and shear modulus is also infiniteD. bulk modulus is zero and shear modulus is also zero. |
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Answer» Correct Answer - A For an ideal liquid,bulk modulus is infinite and shear modulus is zero. |
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| 83. |
What are the qualities of an ideal liquid?A. the bulk modulus is infiniteB. the bulk modulus is zeroC. the shear modulus is inifiteD. the shear modulus is Zero |
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Answer» Correct Answer - A::D An ideal liquid sinout compressible. Hence, change in volume, `Delta V = 0` it means volume strain is zero `B = (F//A)/(Delta V//V) = (F)/(A) xx (V)/(Delta V) = oo` A liquid cannot sustain tangential force. It may contain tangential viscous drag, so `eta = 0` |
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| 84. |
The breaking stress of a wire depends onA. Â length of the wireB. radius of the wireC. material of the wireD. shape of the cross-section |
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Answer» Correct Answer - C The breaking stress of the wire depends upon the nature of the material of the wire. |
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| 85. |
Iron has a BCC structure with atomic radius 0.123 Å. Find the lattice constant.(a) 0(b) 4.587 Å(c) 2.314 Å(d) 0.2840 Å |
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Answer» Correct choice is (d) 0.2840 Å To elaborate: r = 0.123 Å The lattice constant for BCC = 4r/√3 The lattice constant = 0.2840 Å. |
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| 86. |
Which of the following has body centered cubic structure?(a) Polonium(b) Copper(c) Nickel(d) Tungsten |
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Answer» Right choice is (d) Tungsten The explanation is: In tungsten, atoms are arranged in all eight corners and has an additional atom in the centre satisfying the body centered cubic lattice condition. |
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| 87. |
Why are the glasses of building milky?(a) Because of unwanted deposits(b) Because it becomes old(c) Because it is brittle(d) Because it changes in properties |
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Answer» The correct answer is (d) Because it changes in properties To explain: Glasses of the building appear milky because it undergoes heating during the day and cooling during the night. Therefore it acquires some crystalline properties. |
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| 88. |
What is the possible number of different types of lattices (3D)?(a) 4(b) 8(c) 14(d) 17 |
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Answer» Right option is (c) 14 Explanation: According to Bravis, there are only 14 possible ways of arranging points in space lattice from the 7 crystal systems such that, all the lattice points have exactly the same surrounding. |
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| 89. |
What is the lattice constant for FCC crystal having atomic radius 1.476 Å?(a) 1.476 Å(b) 4.1748 Å(c) 5.216 Å(d) 0 |
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Answer» Right choice is (b) 4.1748 Å To explain I would say: Radius=1.476 Å or 1.476 × 10^-10 m Lattice constant for FCC = 4r/√2 Lattice constant = 4.1748 Å. |
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| 90. |
Suppose the object in figure shown is the brass plate of an outdoor sculpture. It experiences shear forces as a result of an erthquake. The frame is 0.80 m and 0.50 cm thick. Calculate the shear strain produced in this object if the displacement x is 0.16 mm. (Shear modulus `=3.5xx10^(10)Pa`) |
| Answer» `"Shear strain"=(x)/(h)=(1.6xx10^(-4)m)/(0.80m)=2.0xx10^(-4)` | |
| 91. |
Find the (i) Net elongation rod approximately. `(x xx 10^(-11)m)` then `x =` (ii) `Y_(eq)` of the composite rod `(x xx 0^(11) N..m^(2))` (assume `A` = area of cross section of each rod),. Then `x =` `l_(1) = l(2) = 1m, F = 2N//m^(2), A = 1sq.m^(2)` `y_(1) = 2xx10^(11) N//m^(2)n, y_(2) = 3xx10^(11) N//m^(2)` ltbr4gt |
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Answer» Correct Answer - (i) 2 (i) `(F)/(A) ((l_(1))/(y_(1)) + (l_(2))/(y_(2)))`, (ii) `(y_(1) y_(2)(l_(1) + l_(2)))/(l_(1) y_(2) + l_(2) y_(1))` (i) `1.67xx10^(-11)m`, (ii) `2.4xx10^(-11) N//m^(2)` |
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| 92. |
An air filled balloon is at a depth of `1 km` below the water level in an ocean . The normal stress of the balloon (in Pa) is (Given,` rho_("water") = 10^(3) kgm^(-3), g = 9.8 ms^(-2)` and `P_(atm) = 10^(5) Pa)`A. `98xx10^(5) N//m^(2)`B. `99xx10^(5) N//m^(2)`C. `98xx10^(3) N//m^(2)`D. `99xx10^(3) N//m^(2)` |
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Answer» Correct Answer - B Net pressure = Pressure due to atomosphere `+` pressure due to water column `= P_(0) + h rho g` |
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| 93. |
An elongation of `0.1%` in a wire of cross-sectional `10^(-6) m^(2)` casues a tension of `100N.Y` for the wire isA. `10^(12) N//m^(2)`B. `10^(11) N//m^(2)`C. `10^(10) N//m^(2)`D. `100 N//m^(2)` |
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Answer» Correct Answer - B `Y = (F)/(A((Delta l)/(l)))` |
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| 94. |
Read each of the statement below carefully and state, with reasons, if it is true or false. (a) The modulus of elasticity of rubber is greater than that of steel. (b) the stretching of a coil is determined by its shear modulus. |
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Answer» Answer: (a) False (b) True) (a) For a given stress, the strain in rubber is more than it is in steel. Young’s modulus, `Y=("Stress")/("Strain")` For a constant stress: `Yprop(1)/("Strain")` Hence, Young’s modulus for rubber is less than it is for steel. (b) Shear modulus is the ratio of the applied stress to the change in the shape of a body. The stretching of a coil changes its shape. Hence, shear modulus of elasticity is involved in this process. |
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| 95. |
Stress is a__quantity.A. Â scalarB. vectorC. tensorD. dimensionless |
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Answer» Correct Answer - C Stress is a tensor quantity. |
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| 96. |
Fluids can developA. Â longitudinal strain onlyB. langitudinal and shearing strainC. longitudinal, shearing and volumetric strainD. Â volumetric strain only |
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Answer» Correct Answer - D Fluids can develop volumetric strain only. |
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| 97. |
Determine the volume contraction of a solid copper cube, 10 cm on an edge when subjected to hydraulic pressure of `7 xx 10^(6)Pa`. Bulk modulus of copper = 140 Gpa. |
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Answer» Length of an edge of the solid copper cube, l = 10 cm = 0.1 m Hydraulic pressure, p = `7.0xx10^(6)` Pa Bulk modulus of copper, B = `140xx10^(9)` Pa Bulk modulus, `B=((p)/(DeltaV))/(V)` Where, `(DeltaV)/(V)` = Volumetric strain `DeltaV` = Change in volume V = Original volume. `DeltaV=(pV)/(B)` Original volume of the cube, `V=l^(3)` `thereforeDeltaV=(pl^(3))/(B)` `=(7xx10^(6)xx(0.1)^(3))/(140xx10^(9))` `=5xx10^(-8)"m"^(3)` `=5xx10^(-2)"cm"^(-3)` Therefore, the volume contraction of the solid copper cube is `=5xx10^(-2)"cm"^(-3)`. |
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| 98. |
A mild steel wire of length `1.0m` and cross sectional area `5.0xx10^(-2)cm^(2)` is stretched, within its elastic limit horizontally between two pillars. A mass of `100g` is suspended form the midpont of the wire. Calculate the depression at the midpoint `(Y_("steel) = 200GPa)` |
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Answer» `x = l [(Mg)/(YA)]^(1//3)`, Here , `2l = 1m, l = 0.5m`, `Mass = 100g = 0.1kg` `Y = 200Gpa = 200xx10^(9)N//m^(2) = 2xx10^(11) N//m^(2)` `x = 0.5 [(0.1xx10)/((2xx10^(11))(0.50xx10^(-6)))]^(1//3) = 1.074xx10^(-2)m` |
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| 99. |
Find the net vertical displacement of point O, when a mass of 2.5 kg is suspended from the mid-point O of the rod shown `(Y=2xx10^(11)N//m^(2))`. |
| Answer» Correct Answer - `2.5m` | |
| 100. |
A heavy metallic rod of non-uniform mass distribution, is hanged vertically from a rigid support. The linear mass density varies as `lambda_((x))=k xx x` where x is the distance measured along the length of rod, from its lower end. Find extension in rod due to its own weight. |
| Answer» Correct Answer - `Deltal=(kgl^(3))/(6AY)` | |