strength of material m.c.q

1) Find the modulus of elasticity for a rod, which tapers uniformly from 35mm to 15mm diameter .The rod is subjected to an axial load of 5KN.If the extension in the rod is 0.025 mm for a length of 300 mm rod
a)145.51GPa b)150 GPa c)155GPa d )160GPa

2) A bar uniform strength follows this condition. If “A”, “a” are areas of upper and lower ends of bar. “W” is the weight per unit volume, S=uniform stress in the bar, L=length of the bar
a) A=a exp(WL/S) b)A=a exp(WLS) c)A=a exp(W/LS) d)none

3) The strain due to temperature change in the bar? If a= coefficient of thermal expansion, t=temperature change
a) at b)a/t c)t/a d)a-t

4) If a material having young’s modulus 1.2*105 N/mm2 and bulk modulus of elasticity of 0.8*105 N/mm2 .Then poisons ratio is
a) 0.5 b) 0.25 c) 0.6 d)0.7

5) If a rigidly connected bar of steel and copper is cooled .then steel bar will be subjected to
a) tension b)compression c)shear d)none

6) Rate of change of bending moment with respect to length of beam is
a) shear force b)shear force per unit area c)zero d)infinite

7)The point where the sign of the bending moment is changing is called as
a)point of inflection b) point of contra flexure c)point of shear d)none

8)A steel plate of 60mm wide &120 mm thick is to be bent into a circular arc of radius 15 m,E=2*105 N/mm2.Then maximum bending stress will be?
a)800N/mm2 b)900N/mm2 c)1000N/mm2 d)none
9)A beam of length L is hinged at both ends ,is used as a column, What is effective length?
a)L b)2L c)L/2 d)3L

10) The ratio of average shear stress to maximum shear stress in case of rectangular beam is ?
a) 1.5 b) 0.66 c) 1 d) 2.

11)A freely supported beam is subjected to udl throughout the span ,the shape of BMD IS
a)rectangle b)equilateral triangle c)parabola d)none

12)Angle between principal planes is
a)360 deg b)90 deg c)45 deg d)0 deg

13)A solid round bar 3 m long&5 cm in diameter is used as strut with both ends hinged .Determine crippling load E=2*105 N/mm2
a) 67.3 KN b)70KN c)77KN d)80KN

14)The mohr’s circle reduces to point when body is subjected to
a)pure shear only
b)uni axial shear only
c)equal and opposite axial stress on two mutually perpendicular planes being free of shear\
d)equal axial stress on mutually perpendicular planes and planes being free of shear

15)A circular rod of 100 mm diameter &500 mm length is subjected to tensile force of 1000 KN. Determine the modulus of rigidity(G).? If E=2*105 N/mm2 and poisons ratio=0.3
a)0.3*105N/mm2 b)0.5*105 N/mm2 c)0.7*105N/mm2 d)0.2*105N/mm2

16)Two shafts A &B are made of same material. The diameter of shaft B is twice that of shaft A. The ratio of power which can be transmitted by shaft A to that of shaft B is
a)1/4 b)1/16 c)1/8 d)1/2

17)The shear stress distribution over a rectangular cross section of a beam follows
a)a straight line path b)an elliptical path c)a circular path d)a parabolic path

18)A shaft is initially subjected to a bending moment and then was subjected to torsion if magnitude of bending moment is found to be same as that of torque, then the ratio of maximum bending stress to shear stress would be
a)0.5 b)0.25 c)2 d)4

19) Thermal stress is function of
a)modulus of elasticity b)coefficient of linear expansion c)change in temperature 4)all of the above

20) The Euler load for column is 1000KN,and crushing load is 1800KN,the Rankine load is equal to
a)600KN b)1000KN c)1500KN d)2500KN

21)____theory which is applied to brittle materials

22)_____theory which is applied to ductile materials

23)formula for factor of safty is_____

24)formula for bulk modulus______

25)Elongation due to selfwight in the cylindrical bar is___of the elongation due to external load

26)Principal planes are the planes having the shear stress value equals to_____

27)The ratio between change in volume to original volume of a body is called as_____

28)unit of volumetric strain_____

29)At maximum bending moment ,shear force equals to____

30)The relationship between youngs modulus E,shear modulus G,when poisons ratio is zero_____

KEY
1)a
2)a
3)a
4)b
5)c
6)a
7)b
8)a
9)a
10)b
11)b
12)b
13)a
14)d
15)c
16)c
17)d
18)c
19)d
20)a
21)maximum normal stress criterion(columbs criterion)
22)maximum distortion energy criterion(von mises criterion)/maximum shearing stress criterion
23)yield point stress/working stress for ductile materials
Ultimate stress/working stress for brittle materials
24)direct stress/volumetric strain
25)0.5 times
26)zero
27)volumetric strain
28)No unit
29)zero
30)E=2G