Q.1
Two rods of different materials having coefficient of linear expansion α1 , α2 and Young's modulii Y1 , Y2 respectively are fixed between two rigid massive walls. the rods are heated such that they undergoes the same increase in temperature. there is no bending of rods. If α1 : α2=2 : 3, the thermal stress developed in two rods are equal provided Y1:Y2 is equal to [ IIT 1989]
  • a)3 : 2
  • b) 1 : 1
  • c)2 : 3
  • d)4 : 9
Q.2
A spherical ball contracts in volume by 0.01%, when subjected to a normal uniform pressure of 100 atmospheres. The bulk modulus of its material in dynes/cm2 is
  • a) 10 ×1012
  • b) 100 ×1012
  • c)1 ×1012
  • d)2 ×1012
Q.3
Two wires A and B are of the same material. their lengths are in ratio 1:2 and the diameters are in ratio 2:If they are pulled by the same force, the increase in length will be in ratio [ MPPMT 1988]
  • a)2 : 1
  • b) 1 : 4
  • c)1 : 8
  • d)8 : 1
Q.4
A thick copper rope of density 1.5×103 kg/m3 and Young's modulus 5×106 N/m2, 8 m in length is hung from the ceiling of a room. The increase in its length due to its own weight is [ CPMT 1998]
  • a) 9.6×10-2 m
  • b) 19.2×10-7 m
  • c) 9.6×10-3 m
  • d) 9.6 m
Q.5
The upper end of a wire of radius 4mm and length 100 cm is clamped and its other end is twisted through an angle of 30°. Then angle of shear is [ NCERT 1990]
  • a)12°
  • b) 0.12°
  • c)1.2°
  • d)0.012°
Q.6
A cube at temperature 0°C is compressed equally from all sides by an external pressure P. By what amount should its temperature be raised to bring it back to the size it had before the external pressure was applied. the bulk modulus of the material of the cube is K and the coefficient of linear expansion is α [ CPMT 1998]
  • a) P / Kα
  • b) P/ 3Kα
  • c)3Pα / K
  • d) 3K/ P
Q.7
When a force is applied on a wire of uniform cross-sectional area 3×10-6 m2 and length 4m, the increase in length is 1mm. Energy stored in it will be [ Y=2×1011 N/m2] [ MP PET 1995]
  • a) 6250 Joule
  • b) 0.177 Joule
  • c)0.075 Joule
  • d)0.150 Joule
Q.8
A steel ring of radius r and cross-section area 'A' is fitted onto a wooden disc of radius R(R>r). If young's modulus be E, then the force with which the steel ring is expanded is [ AP 1986]
  • a)
    ch-8_qn-92choice_img_no1.png
  • b)
    ch-8_qn-92choice_img_no2.png
  • c)
    ch-8_qn-92choice_img_no3.png
  • d)
    ch-8_qn-92choice_img_no4.png
Q.9
The extension of wire by the application of load is 3mm. The extension in a wire of the same material and length but half the radius by the same load [ CPMT 1990]
  • a)12 mm
  • b) 0.75 mm
  • c)6 mm
  • d)15 mm
Q.10
A material has Poisson's ratio 0.if a uniform rod of it suffers a longitudinal strain of 2×10-3, then the percentage change in volume is [ AP1987]
  • a) 0.6
  • b) 0.4
  • c)0.2
  • d)zero
Q.11
The poisson ratio can not have the value [ EAMCET 1989]
  • a) 0.7
  • b) 0.2
  • c)0.1
  • d)0.5
Q.12
Streamline flow is more likely for liquids with
  • a) High density an low viscosity
  • b) Low density and high viscosity
  • c)High density and high viscosity
  • d)Low density and low viscosity
Q.13
The compressibility of water is 4×10-5 per unit atmospheric pressure. The decrease in volume of 100cm3 of water under a pressure of 100 atmospheres will be [ MPPMT 1990]
  • a) 0.4 cm3
  • b) 4×10-5 cm3
  • c)0.025 cm3
  • d)0.04 cm3
Q.14
Two cylinder A and B are made of the same material. the length and radii of the two cylinder are in the ratio of 1 :Both are twisted by the same external torque. the ratio of the angle of twist of A and B is
  • a) 1: 2
  • b) 1 : 4
  • c)1 : 8
  • d)8 : 1
Q.15
Two cylinder A and B of the same material have same length, the radii of A and B are in the ratio of 1:The two are joined end to end as shown in figure. The upper end of A is rigidly fixed. The lower end of B is twisted through an angle θ, the angle of twist of cylinder A is
ch-8_que_no-100_img_no1.png
  • a) θ
  • b) (15/16) θ
  • c) (16/17)θ
  • d) (17/16) θ
Q.16
In steel the Young's modulus and strain at the breaking point are 2×1011Nm-2 and 0.15 respectively. The stress at the break point for steel is therefore [ MPPET 1990]
  • a)1.33 × 1011Nm-2
  • b) 1.33×1012Nm-2
  • c)7.5×10-3 Nm-2
  • d)3×1010Nm-2
Q.17
Which of the following statement is correct? [ MPPET 1992]
  • a) Hook's law is applicable only within elastic limit
  • b) The adiabatic and isothermal elastic constant of gas are equal
  • c)Young's modulus is dimensionless
  • d)Stress multiplied by strain is equal to the stored energy
Q.18
The force required to stretch a steel wire of 1cm2 cross-section to 1.1 times its length would be ( Y=2×1011 Nm-2) MPPER 1992]
  • a) 2×106 N
  • b) 2×103 N
  • c)2×10-6
  • d)2×10-7 N
Q.19
Which of the following substance possesses the highest elasticity [ MPPMT 1992]
  • a) Rubber
  • b) Glass
  • c) Steel
  • d) Copper
Q.20
Which of the following quantities does not have the unit of force per unit area [ MPPMT]
  • a)Stress
  • b) Strain
  • c)Young's modulus of elasticity
  • d)Pressure
Q.21
A rod of length l and radius 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 rigid base and the free end of larger rod is given a twist of θ°, the twist angle at the joint will be
  • a) θ/4
  • b) θ/2
  • c)(5/6) θ
  • d)(8/9) θ
Q.22
As steel wire has length 2.0 m, radius 1.0 mm and Y=20×1010 N/mA sphere of mass 10 kg is attached to one end of the wire ,which is then whirled in a vertical circle with an angular velocity of 2 revolutions per sec. The elongation of wire when the mass is at lowest point of the path is nearly [ AMU 1995]
  • a)1.0 mm
  • b) 2.0 mm
  • c)0.1 mm
  • d)0.01 mm
Q.23
Two wires of the same material have lengths in ratio 1:2 and their radii are in the ratio 1 :√If they are stretched by applying equal force, the increase in their lengths will be in the ratio.. [ MPPMT 1994]
  • a) 2 : √2
  • b) √2 : 2
  • c) 1 : 1
  • d) 1 : 2
Q.24
A uniform cube is subjected to volume compression. If each side is increased by 1% then bulk strain is .. [ EAMCET 1995]
  • a)0.01
  • b) 0.06
  • c)0.02
  • d)0.03
Q.25
A cylinder tree has a breaking stress of 106 N/mThe density of the tree is 2×104 kg/mThe maximum possible height of the tree is then [ CET 1994]
  • a) 25 m
  • b) 150 m
  • c)5.0 m
  • d)100 m
Q.26
A force of 103 N stretches the length of a hanging wire by 1 millimeter. The force required to stretch a wire of same material and length but having four times the diameter by 1 millimetre is [ PMT 1995]
  • a) 4×103 N
  • b) 16×103 N
  • c)(1/4)×103 N
  • d)(1/16)×103 N
Q.27
When a weight of 10 kg is suspended from a copper wire of length 3 metres and diameter 0.4 mm, it length increases by 2.4 cm. If the diameter of the wire is doubled, then the extension in its length will be [ MPPMT 1994]
  • a) 9.6 cm
  • b) 4.8 cm
  • c) 1.2 cm
  • d) 0.6cm
Q.28
When a 4 kg mass is hung vertically on a light spring that obeys Hook's law, the spring stretches by 2cm. The work required to be done by an external agent in stretching this spring by 5cm will be ( g=9.8 m/s2[ PMT 1995]
  • a)4.900 Joule
  • b) 2.450 Joule
  • c)0.495 Joule
  • d)0.245 Joule
Q.29
A 2 m long rod of radius 1cm, which is fixed from one end is given twist of 0.8 radians. The shear strain developed will be [ Raj.PET 1997]
  • a) 0.002
  • b) 0.004
  • c)0.008
  • d)0.016
Q.30
A body of mass 10 kg is attached to a wire 30 cm long. It breaking stress is 4.8 ×107 Nm-The area of cross-section of the wire is 10-6 mWhat is the maximum angular velocity with which it can be rotated in horizontal circle [ CPMT 1998]
  • a) 1 rad/s
  • b) 2 rad/s
  • c)4 rad/s
  • d)8/rad/s
0 h : 0 m : 1 s