Loading [MathJax]/jax/output/CommonHTML/jax.js

CBSE Questions for Class 11 Engineering Physics Mechanical Properties Of Solids Quiz 12 - MCQExams.com

A wire of density 9gm/cm2 is stretched between two clamps 1.00 m apart subjected extension of 0.05 cm. The lowest frequency of transverse vibrations in the wire is 
(Assume Young's modulus Y = 91010N/m2)
  • 35 Hz
  • 45 Hz
  • 75 Hz
  • 90 Hz
The isothermal bulk modulus of an ideal gas at pressure 'P" is 
  • P
  • yP
  • P/2
  • P/r
The relation between Young's modulus (Y), bulk modulus (K) and modulus of elasticity (n) is 
  • 1/y=1/k=3/n
  • 3/y=1/n+1/3k
  • 1/y=3/n+1/3k
  • 1/n=3/y+1/3k
The ratio of lateral contraction strain to the longitudinal elongation strain of a stretched wire when the volume of the wire remains constant is :
  • 1
  • 1/2
  • 2
  • 3/2
A sphere contracts in volume by 0.01% when taken to the bottom of sea 1 km deep. Find Bulk modulus of the material of the sphere.
  • 1.2×1010N/m2
  • 9.8×1011N/m2
  • 9.8×1010N/m2
  • 9.8×106N/m2
In an experiment, bras and steel wires of length lm each with areas of cross section 1mm2 are used. the wires are connected in series and one end of the combined wire is connected to a rigid support and other end is subjected to elongation. The stress required to produce a net elongation of 0.2mm is :
(Given, the Young's Modulus for steel and brass are respectively, 120×109N/m2 and 60×109N/m2)
  • 0.2×106N/m2
  • 4.0×106N/m2
  • 1.8×106N/m2
  • 1.2×106N/m2
1022 particle each of mass 1026Kg are striking perpendicularly on a wall of area 1m2 with speed 104m/s in 1sec. The pressure on the wall if collisions are perfectly elastic is:
  • 2N/m2
  • 4N/m2
  • 6N/m2
  • 8N/m2
Two elastic wire A&B having length A=2m and B=1.5m and the ratio of young's modules YA:YB is 7:4. If radius of wire B(rB) is 2mm then choose the correct value of radius of wire A. Given that due to application of the same force charge in length in both A&B is same
  • 1.7mm
  • 1.9mm
  • 2.7mm
  • 2mm
For an equal stretching force F, the Young's modulus (Ys) for steel and rubber (Yr) are related as
  • Ya=Yr
  • Ys<Yr
  • Ys>Yr
  • YsYr
If F is the force applied to an elastic bar to produce an extension of Δ. The, the energy lost in the process is 
  • F.Δ
  • F.Δ2
  • zero
  •  3F.Δ2
The relation between γ,μ and K for a elastic material is
  • 1μ=13γ+19K
  • 1K=13γ+19μ
  • 1γ=13K+19μ
  • 1γ=13μ+19K
An elastic string of length 42sm and cross-sectional area 104m2 is attached between two pegs ar distance of 6mm as shown in the figure. A particle of mass m is kept at midpoint of string and stretched as shown in figure by 20cm and release. As the string its natural length, the particle attains a speed of 20m/s. Then young modulus Y of string is of order
1611238_3e3bb6e6a9154042bfcd33719b0a374d.png
  • 108
  • 1012
  • 106
  • 104
A block of mass 4kg is suspended from the ceiling with the help of a steel wire of radius 2mm and negligible mass. Find the stress in the wire.(g=π2)
1611353_bf408a687d294c488f9d729585bd0ea7.png
  • 4.0×106N/m2
  • 3.14×106N/m3
  • 3×105N/m3
  • 2.0×106N/m2
Select the correct alternative (s)
a) Elastic forces are always conservative
b) Elastic forces are not always conservative
c) Elastic forces are conservative only when Hooke's law is obeyed
d) Elastic forces may be conservative even when Hooke's law is not obeyed
  • a,d
  • b,c
  • b,d
  • a,c
A rubber cord of density d, Youngs modulus Y and length L is suspended vertically. If the cord extends by a length 0.5 L under its own weight, then L is
  • Y2dg
  • Ydg
  • 2Ydg
  • dg2Y
  • dgY
A fixed volume of iron is drawn into a wire of length L. The extension x produced in the wire by a constant force F. F is proportional to ______.
  • 1L2
  • 1L
  • L2
  • L
The graph shows the extension of a sample of a type of rubber as different loads F are applied and then gradually removed.
What is the best estimate of the strain energy in the rubber when a load of 80 N is applied?

1641897_2ac42be4e85f48aa93d9817b4f812d1f.png
  • 0.40 J
  • 0.64 J
  • 0.88 J
  • 1.3 J
To determine the Young modulus of a wire, several measurements are taken.
In which row can the measurement not be taken directly with the stated apparatus?
  • measurement : area of cross-section of wire ; apparatus : micrometer screw gauge
  • measurement : extension of wire ; apparatus : vernier scale
  • measurement : mass of load applied to wire ; apparatus : electronic balance
  • measurement : original length of wire ; apparatus : metre rule
The amount of water in slug containing by a cylindrical vessel of length 10cm and cross-sectional radius 5cm is?(The density of water is 1000 kg/m3):
  • 157×103 slug
  • 53.76×103 slug
  • 10.7 slug
  • 14.6 slug
Which of the following statement related to stress-strain relation is correct?
  • Stress is linearly proportional to strain irrespective of the magnitude of the strain
  • Stress is linearly proportional to strain above
  • Stress is linearly proportional to strain for stress much smaller than at the yield point
  • Stress-strain curve is same for all materials
  • Stress is inversely proportional to strain
The bulk modulus for an incompressible liquid is?
  • 0
  • 1
  • 2
Theoretically the value of Poisson's ratio σ lies between:
  • 0<σ<1
  • 1<σ<0.5
  • 0.2<σ<0.4
  • 1<σ<1
Three blocks system is shown in the figure. Each has mass 3 kg. String connected to P and Q are of equal cross-section and Young's modulus of 0.005 cm2 and 2×1011N/m2 respectively, neglect friction. The longitudinal strain in A and B are.
1703210_1c8b843e8226414899102cc170b984e0.png
  • 2.5×104,1×104
  • 1×104,2×104
  • 0.2×104,2×104
  • None of these
The pressure applied from all directions on a cube is P. How much its temperature should be raised to maintain the original volume? The volume elasticity of the cube is B and the coefficient of volume expansion is γ:
  • PγB
  • PγB
  • PBγ
  • γBP
A one metre long steel wire of cross-sectional area 1 mm2 is extended by 1 mm. If Y=2×1011Nm2, then the work done is?
  • 0.1 J
  • 0.2 J
  • 0.3 J
  • 0.4 J
Young's modulus is defined for:
  • Solid
  • Liquid
  • Gas
  • All of these
The bulk modulus of water is 2.1×109 N/m2. The pressure required to increase the density of water by 0.1% is :
  • 2.1×103 N/m2
  • 2.1×106 N/m2
  • 2.1×105 N/m2
  • 2.1×102 N/m2
From the ceiling, a light rod of length 200 cm is suspended horizontally with the help of two vetical wires of equal lenght as shown in figure. If one wire is made of brass and have cross-sectional area 0.2 cm2 and other of steel of 0.1 cm2 of cross-sectional area, then at what distance along rod a weight may be hung to produce equal stress in both the wires?
1703228_bd0d9c15b1f149e2a2b53117e57f2d0f.png
  • 43 m from steel wire
  • 43 m from brass wire
  • 1 m from steel wire
  • 14 m from brass wire
A long wire hangs vertically with its upper end clamped. A torque of 8 Nm applied to the free end twisted it through 45o, the potential energy of the twisted wire is?
  • π joule
  • π2 joule
  • π4 joule
  • π8 joule
The dimensions of Poisson's ratio is?
  • [M0L0T0]
  • [ML1T2]
  • [ML2T4]
  • [ML2T3]
The stress for one litre of a perfect gas, at a pressure of 72 cm of Hg, when it is compressed isothermally to a volume of 900 cc, is?
  • 9.88×103 N/m2
  • 10.88×103 N/m2
  • 1.088×103 N/m2
  • 2×103 N/m2
Choose the correct statements from the following
  • Steel is more elastic than rubber
  • The stretching of a coil spring is determined by the Young's modulus of the wire of the spring
  • The frequency of a tuning fork is determined by shear modulus of the material of the fork
  • When a material is subjected to a tensile (stretching) stress the restoring forces are caused by interatomic attraction
Which of the following are correct?
  • The product of bulk modulus of elasticity and compressibility is 1
  • A rope 1 cm in diameter breaks if the tension in it exceeds 500 N. The maximum tension that may be given to a similar rope of diameter 2 cm is 2000 N
  • Both a and b are correct
  • Neither a nor b is correct
If for a material, Y and B are Young's modulus and Bulk modulus then:
  • Y<3B
  • Y=3B
  • Y>3B
  • 3Y=B
A given quantity of an ideal gas is at the pressure P and the absolute temperature T. The isothermal bulk modules of the gas is :
  • 23P
  • P
  • 32P
  • 2P
When water freezes inside a pipe, it expands by about 9% due to expansion. What would be the pressure increase inside the pipe? The bulk modulus of ice is 200×109 N/m2.  
  • 1.80×1010 N/m2
  • 3.60×108 N/m2
  • 9×107 N/m2
  • 7.2×108 N/m2
A rod of length 1000 min and coefficient of linear expansion α=104 per degree is placed symmetrically between fixed walls separated by 1001 mm. The Young's modulus of the rod is 1011 N/m2. If the temperature is increased by 20oC, then the stress developed in the rod is (in N/m2):
  • 10
  • 2×108
  • 108
  • Cannot be calculated

1745851_d4d6f7c2a893489dba2a515bef81beb5.png
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Both Assertion and Reason are incorrect
A vertical bar of uniform section is fixed at both of its ends and a load W=5000 N is applied axially at an intermediate section as shown in figure.
Select the correct statements (s):
1745613_fd28c516f45a4b1a8173879e8e515d31.png
  • Reaction at the bottom support is 3000 N
  • Reaction at the bottom support is 2000 N
  • Reaction at the top support is 1000 N
  • Reaction at the top support is 3000 N
Select the correct information:
  • Work done in stretching =12Y× (stress)2
  • For constant volume poisson's ration σ=0.5
  • normal stress causes shear strain always
  • Stress caused by heating is independent of length
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
  • l2
  • None of the above
In CGS system, the Young's modulus of a steel wire is 2×1012. To double the length of a wire of unit cross section area, the force required is

  • 4×106dynes
  • 2×1012dynes
  • 2×1013newtons
  • 2×108dynes
To double the length of a iron wire having 0.5cm2 area of cross- section, the required force will be (Y=1012dyne/cm2)

  • 1.0×107N
  • 1.0×107N
  • 0.5×107N
  • 0.5×1012dyne
If Youngs modulus of iron is 2×1011N/m2 and the interatomic spacing between two molecules is 3×1010metre, the interatomic force constant is

  • 60N/m
  • 120N/m
  • 30N/m
  • 180N/m
A copper and a steel wire of the same diameter are connected end to end A deforming force F is applied to this composite wire which causes a total elongation of 1cm. The two wires will have:
1795336_62cffd2e697f418f93daf289e5bd39bd.png
  • The same stress
  • Different stress
  • The same strain
  • Different strain
The force required to stretch a steel wire of 1cm2 cross-section to 1.1 times its length would be (Y=2×1011Nm2

  • 2×106N
  • 2×103N
  • 2×106N
  • 2×107N
A steel wire is stretched with a definite load. If the Young's modulus of the wire is Y. For decreasing the value of Y

  • Radius is to be decreased
  • Radius is to be increased
  • Length is to be increased
  • None of the above
Which statement is true for a metal

  • Y<η
  • Y=η
  • Y>η
  • Y<1η
The length of a rod is 20cm and area of cross-section 2cm2. The Young's modulus of the material of wire is 1.4×1011N/m2 . If the rod is compressed by 5kgwt along its length, then increase in the energy of the rod in joules will be

  • 8.57×106
  • 22.5×104
  • 9.8×105
  • 45.0×10(5)
The spring balance does not read properly after its long use, because

  • The elasticity of spring increases
  • The elasticity decreases
  • Its plastic power decreases
  • Its plastic power increases
0:0:2


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 11 Engineering Physics Quiz Questions and Answers