Strength of Materials Sample Objective

3. In an experiment it is found that the bulk modulus of a
material is equal to its shear modulus. The poison’s ratio
is

(a) 0.125
(b) 0.250
(c) 0.375
(d) 0.500

4. The ability of material to absorb a large amount of
energy is :

(a) Ductility
(b) Hardness
(c) Toughness
(d) Resilience

5. For metals which do not have a well- define yield
point, the proof stress is determined by drawing a line
parallel to he initial tangent at an offset of m :

(a) 0.2 %
(b) 0.5 %
(c) 1.0 %
(d) 2.0 %

6. Match list - I (Mechanical property) with list - II
(Feature) and select the correct answer using the codes
given below the lists:

List - I - List - II
A. Creep 1. Amenability to go through changes of shape
without rupture.
B. Tenacity - 2. Susceptibility to deform with the time under
sustained loading.
C. Ductility - 3. Ultimate tensile strength
D. Brittleness - 4. Susceptibility to fail suddenly without warning.

Codes :

ABCD
(a) 4 1 3 2
(b) 2 3 1 4
(c) 4 3 1 2
(d) 2 1 3 4

7. Match list - I with list - II and select the correct answer

using codes given below the lists:

List- I (Materials) List - II (characteristic)

A. Inelastic material - 1. No plastic zone

B. Rigid plastic material - 2. Large plastic zone

C. Ductile material - 3. Strain is not recovered after

unloading

D. Brittle material - 4. Strain is zero up to a stress level and

then stress remains constant.

Codes :

ABCD

(a) 3 4 2 1

(b) 3 4 1 2

(c) 4 3 2 1

(d) 4 3 1 2

8. Match list -I with list - II and select the correct answer

using the codes given below the lists:

List- I (Property) List- II (characteristic)

A. Fatigue - 1. Material continues to deform with time

under sustained loadings.

B. Creep - 2. Decreased resistance of material to

repeated reversals of stress.

C. Plasticity - 3. Material has a high probability of not

failing under reversals of stress of

magnitude below the lists:

D. Endurance limit - 4. Material continues to deform without any

further increase in stress.

Codes :
ABCD

(a) 2 1 4 3
(b) 2 1 3 4
(c) 1 2 4 3
(d) 1 2 3 4

9. Match list-I with list-II and select the correct answer

using the codes given below:

List - I List-II

(various test stages) (Observation)

A. I stage - 1. Yield point

B. II stage - 2. Limit of proportionality

C. III stage - 3. Breaking stress

D. IV stage - 4. Ultimate stress

Codes :
ABCD

(a) 2 1 3 4
(b) 2 1 4 3
(c) 1 2 4 3
(d) 1 2 3 4

10. Which of the following statement is false?
(a) The stress dependent part of the plastic deformation is
referred to as creep, and the time dependent part which is
also influenced by the temperature as slip.
(b) In case of ductile material possessing a well-defined
yield point, the proportional limit almost coincides.
(c) A fatigue failure is of a brittle nature even for
materials which are normally ductile.
(d) The endurance limit for machined and polished
specimens is higher than for rolled or fogged components

Question 11 to 30 will carry 2 marks each
11. Two bars of same size but of different materials are
subjected to same tensile force. If the bars have their
elongation in the ratio of 4 : 6, then the ratio of modulus
of elasticity of the two materials would be .
(a) 4 : 6
(b) 6 : 4
(c) 4 : 10
(d) 16 : 36

12. A mild steel bar is 40 cm long. The lengths of parts
AB and BC of the bar 20 cm each. it is loaded as shown
in the given fig. The ratio of the stresses 1 in part AB to
2 in part BC is. P1 = 1000 kg, P2 = 1000 kg.

(a) 2
(b) 0.5
(c) 4
(d) 0.25

13. The volumetric strain of a cylindrical shell with an
internal pressure is equal to.
(a) 2 longitudinal strain net circumferential strain.
(b) 2 longitudinal strain 1/2 net circumferential strain.
(c) 1/2 longitudinal strain 1/2 net circumferential strain.
(d) longitudinal strain 2 net circumferential strain.

14. A steel cube of volume 8000 cc is subjected to all
round stress of 1330 kg/cm2. The bulk modulus of the
material is 1.33 x 106 kg/cm2. The volumetric change is.
(a) 8 cc
(b) 6 cc
(c) 0.8 cc
(d) 103cc

15. An elastic bar of length ‘L’, cross- sectional area A,
young’s modulus of elasticity E and self-weight W is
hanging vertically. It is subjected to a load P applied
axially at the bottom end. The total elongation of the
bar is given by.
(a) WL / AE + PL / AE
(b) WL / 2AE + PL / AE
(c) WL / 2AE + PL / 2AE
(d) WL / AE + PL /2 AE.

16. A prismatic bar of volume ‘V’ is subjected to a
compressive force in the longitudinal direction. if the
Poisson’s ratio of the material of the bar is and the
longitudinal strain is ‘e’ then the final volume of the bar
will be .
(a) (1 + e) (1- )2 V.
(b) (1 - e2) (1 +  e) V.
(c) (1 + e) (1 +  e)2 V.
(d) (1 - e) (1 + e )2 V.
17. A square bar of certain material with 4 cm side, is
subjected to a pull of 16 T, where by the extension is
0.1cm in a length of 200 cm. If the Poisson’s ratio is 1/4,
the rigidity modulus of the material in kg / cm2 .
(a) 2 x 106
(b) 1.6 x 106
(c) 1.8 x 106
(d) 0.8 x 106

18. A cylindrical bar of 20 mm diameter and 1 m length is
subjected to a tensile test. its longitudinal strain is 4 times
that of its lateral strain. if the modulus of elasticity is 2 x
105 N / mm2. then its modulus of rigidity will be.
(a) 8 x 106 N / mm2
(b) 8 x 105 N / mm2
(c) 0.8 x 104 N / mm2
(d) 0.8 x 105 N / mm2.

19. A round bar made of same material consists of 3 parts
each of 100 mm length having diameters of 40mm, 50mm
and 60 mm respectively. If the bar is subjected to an axial
load of 10kN, the modulus elasticity E is given in kN/
mm2 . the change n length of the bar in ‘mm’ is .

(a) (0.4 /E) (1/16 + 1/25 + 1/36) mm
(b) (4 /E) (1/16 + 1/25 + 1/36) mm
(c) (0.4 /E) (1/16 + 1/25 + 1/36) mm
(d) (40 /E) (1/16 + 1/25 + 1/36) mm.

20. The shear modulus of most materials with respect to
the module of elasticity is.

(a) More than half
(b) Less than half
(c) Equal to half
(d) Unrelated

21. A plate of 1 mm thick and 5 cm wide has a rivet hole
of diameter 1 cm as shown in fig. It is subjected to a load
of 1000 N. the maximum tensile stress in the plate is
approximately .

(a) 20 MPa
(b) 25 MPa
(c) 60 MPa
(d) 75 MPa

22. A steel rod of circular section tapers from 2 cm
diameter to 1 cm diameter diameter over a length of 50
cm. If the modulus of elasticity of the material is 2 x 106
kg/cm2, then the increase the length under a pull of 3000
kg will be.
(a) 0.3/2cm
(b) 30 / cm
(c) 300 / 
(d) 750 cm

23. A square bar of certain material with 4 cm side, is
subjected to a pull of 16 T, where by the extension is
0.1cm in a length of 200 cm. If the Poisson’s ratio is 1/4,
the rigidity modulus of the material in kg / cm2 .
(a) 2 x 106
(b) 1.6 x 106
(c) 1.8 x 106
(d) 0.8 x 106

24. A bar 4 cm in diameter is subjected to an axial load of
4 t . The extension of the bar over a gauge length of 20
cm is 0.03 cm. The decrease in dia is 0.0018 cm. The
Poisson’s ratio is
(a) 0.25
(b) 0.30
(c) 0.33
(d) 0.35

25. A free bar of length 1 is uniformly heated from 00C to
a temperature 10C.  is the coefficient of linear expansion
and E the nodules of elasticity. The stress in the bar is
[GATE-1992][ME]
a) tE
b) tE/2
c) zero
d) none of these

26. Two identical circular rods of same diameter and
same length are subjected to same magnitude or axial
tensile force. One of the rod is made out of mild steel
having the modulus of elasticity of 206 GPa. The other
rod is made out of cast iron having the modulus of
elasticity of 10 GPa. Assume both the materials to be
homogeneous and isotropic and the axial force causes the
same amount of uniform stress in both the rods. The
stresses developed are with in the proportional limit of the
respective materials. Which of the following observations
is correct ?
[GATE-03][ME]

a) Both rods elongate by the same amount
b) Mild steel rod elongates more than the cast iron
c) Cast iron rod elongates more than the mild steel rod
d) As the stresses are equal strains are also equal in both
the rods

27. If a steel tyre is heated and struck on a rigid wheel
after cooling the tyre will de subjected to .
(a) Normal compression
(b) Normal tension
(c) Hoop compression
(d) Hoop tension

28. A steel frame is fitted with an equal length of an
aluminum rod at room temp. (Total area of steel = area of
aluminum 200mm2 ).When fitted they are in stress free
state. Given Es = 210GPa; Ea= 70 GPa; s = 12.5 x 10-6
/ 0C, a = 25 x 10-6 / 0C, for a temperature rise of 800C
the load in the aluminum bar is .

(a) 21.0kN
(b) 18kN
(c) 15.8 kN
(d) 10.5 kN

29. A steel bar of 2m length is fixed at both ends at 200,
The coefficient of thermal expansion is 11 x 106 / 0C and
the modulus of elasticity is 2 x 106 kg / cm2. If the
temperature is changed to 180C, then the bar will
experience a stress of .
(a) 22 kg / cm2 (tensile)
(b) 22 kg / cm2 (compressive)
(c) 44 kg / cm2 (compressive)
(d) 44 kg / cm2 (tensile)

30. A 600 mm long and 50 mm diameter rod of steel (E =
200 GPa, =12 x 106 / 0C) is attached at the ends to
unyielding supports. When the temperature is 300C there
is no stress in the rod. After the temperature of the rod
drops to 200C, the axial stress in the rod will be.
(a) 24 MPa (tensile)
(b) 72 MPa (compressive)
(c) 120 MPa (tensile)\
(d) 144 MPa (compressive).

TEST PAPER : UNIT - I (ANS.)
1-a, 2-b, 3-a, 4-c, 5-a, 6-b, 7-a, 8-a, 9-b, 10-b, 11-b, 12-b,
13-d, 14-a, 15-b, 16-d, 17-d, 18-d, 19-b, 20-b, 21-b, 22-a,
23-b, 24-b, 25-c, 26-c, 27-d, 28-d, 29d, 30-a.