Strength of Materials - Stress and Strain
Exam Duration: 45 Mins Total Questions : 20
There is always a limiting value of load upto which the strain totally disappears on the removal of load, the stress corresponding to this load is called
- (a)
elastic limit
- (b)
yield stress
- (c)
unit stress
- (d)
None of these
Total elongation produced in a bar due to its self-weight is given by
- (a)
\(\frac{\rho gl^2}{E}\)
- (b)
\(\frac{\rho gl^2}{2E}\)
- (c)
\(\frac{\rho gl}{E}\)
- (d)
\(\frac{\rho^2 gl}{E}\)
The elongation of a circular tapered rod is given by
- (a)
\(\frac{4Pl}{\pi Ed_1d_2}\)
- (b)
\(\frac{2Pl}{\pi Ed_1d_2}\)
- (c)
\(\frac{4Pl}{\pi Ed_1^2d_2}\)
- (d)
\(\frac{4Pl}{Ed_1d_2}\)
Relation between E, K and G is given by
- (a)
\(E=\frac{9KG}{3K+G}\)
- (b)
\(E=\frac{3K+G}{6KG}\)
- (c)
\(E=\frac{6KG}{K+3G}\)
- (d)
\(E=\frac{3KG}{3K+G}\)
Strain in a direction at right angle to the direction of applied force is known as
- (a)
lateral strain
- (b)
shear strain
- (c)
volumetric strain
- (d)
None of these
Maximum stress (\(\sigma_{max}\)) induced in a bar of length l, rotating at an angular velocity \(\omega\) , is given by
- (a)
\(\frac{1}{2}\rho \omega^2l^2\)
- (b)
\(\frac{1}{8}\rho \omega^2l^2\)
- (c)
\(\rho \omega^2l^2\)
- (d)
\(\rho \omega^2l^2\)
However complex the state of stress may be in a body the number of principal planes are always
- (a)
2
- (b)
3
- (c)
4
- (d)
1
The normal stress on a plane whose normal is inclined at angle θ with the line of action of the uniaxial stress σx is given by
- (a)
σx l cos2θ
- (b)
σx l sin2θ
- (c)
σx cos2θ
- (d)
σx sin2θ
In the case of biaxial state of normal stresses, the maximum shear stress is equal to
- (a)
the sum of the normal stresses
- (b)
the difference of normal stresses
- (c)
half the difference of normal stresses
- (d)
half the sum of normal stresses
For a two dimensional stress system, the coordinates of the centre of Mohr's circle are
- (a)
\((\frac{\sigma_X-\sigma_Y}{2},0)\)
- (b)
\((0,\frac{\sigma_X+\sigma_Y}{2})\)
- (c)
\((\frac{\sigma_X+\sigma_Y}{2},0)\)
- (d)
\((0,\frac{\sigma_X-\sigma_Y}{2})\)
A point in two dimensional stress state, is subjected to biaxial stress as shown in the given figure. The shear stress acting on the plane AB is
- (a)
zero
- (b)
\(\sigma\)
- (c)
\(\sigma cos^2\theta\)
- (d)
\(\sigma sin\theta cos\theta\)
Match List I with List II and select the correct answer using the codes given below the lists
List I | List II |
---|---|
1.Pure uniaxial compression | |
2.Pure shear | |
3.Pure biaxial tension having sam e magnitude | |
4.Pure biaxial tension |
- (a)
P Q R S 1 2 3 4 - (b)
P Q R S 4 3 2 1 - (c)
P Q R S 2 4 1 3 - (d)
P Q R S 2 1 3 4
The radius of the Mohr's circle gives the value of
- (a)
maximum normal stress
- (b)
minimum normal stress
- (c)
maximum shear stress
- (d)
minimum shear stress
If principal stresses are as σx=65 MN/m2, σy=+20 MN/m2 , σz =-85 MN/m2 and μ=0.3, E=200 GN/m2, then principal strain ex is
- (a)
0.422x10-3
- (b)
0.13x10-3
- (c)
0.552x10-3
- (d)
None of these
In the given figure, \(\frac{E_{Al}}{E_{Cu}}=2,\frac{l_2}{l_1}=1.5, d_{Cu}=30mm, d_{Al}=37.5mm\) . If bar remains horizontal after load P is applied, then ratio of forces in the bar, ρAl/ρCu is
- (a)
1.2
- (b)
3.7
- (c)
2.08
- (d)
4.1
In given figure,
AAl=2 mm2, ACu =1 mm2 and EAl /ECu=2
A load P = 10 kN is applied at a distance b from AI rod, such that bar 1 remains horizontal. Select the correct option
- (a)
σAl=σCu
- (b)
ρAl=ρCu
- (c)
eAl=eCu
- (d)
All of these
In given figure,
AAl=2 mm2, A Cu =1 mm2 and E Al /ECu=2
A load P = 10 kN is applied at a distance b from AI rod, such that bar 1 remains horizontal. Value of b is
- (a)
170 mm
- (b)
106 mm
- (c)
110 mm
- (d)
152 mm
In the given figure,
Principal stresses are
- (a)
112 N/mm2, 67.64 N/mm2
- (b)
100 N/mm2 , 60 N/mm2
- (c)
120 N/mm2, zero
- (d)
zero, -100 N/mm2
In the given figure,
Maximum shear stress is
- (a)
110 N/mm2
- (b)
44.36 N/mm2
- (c)
62 N/mm2
- (d)
77.63 N/mm2
If E=200 GPa and μ=0.283 for this block material then, change in volume due to these complex stresses is
- (a)
100 mm3
- (b)
120 mm3
- (c)
125 mm3
- (d)
135 mm3