Strength of Materials (Stresses and Strains)
Q.1. A bar of diameter 30 mm is subjected to a tensile load such
that the measured extension on a gauge length of 200 mm is 0.09 mm and the change
in diameter is 0.0045 mm. The Poisson’s ratio will be
(a) 1/4
(b) 1/3
(c) 1/4.5
(d) 1/2 (IES
1995)
Q.2. A steel cube of volume 8000 cc is subjected to all round stress
of 1330 kg/sq.cm. The volumetric change is
(a) 8 cc
(b) 6 cc
(c) 0.8 cc
(d) 0.01 cc (IES
1995)
Q.3. A steel tube is surrounding a solid aluminium cylinder. A force
P is applied at the assembly. The aluminium cylinder is 75 mm in diameter and
outside diameter of the steel tube is 90 mm. Given Esteel = 200 GNm-2
and Ealuminium =25 GNm-2 If P = 200 kN, the stress in
steel tube will be
(a) 10 MPa
(b) 60.75 MPa
(c) 80.25 MPa
(d) 100 MPa
Q.4. In the above problem, stress in aluminium will be
(a) 10 Mpa
(b) 60.75 MPa
(c) 80.25 MPa
(d) 100 MPa
Q.5. A bar of length L is fitted between two supports and the
temperature is increased t0. If support does not yield, the
temperature stress in the bar will be
(a) 0
(b) tE
(c) at
(d) atE
Q.6. The length, coefficient of thermal expansion and Young’s
modulus of bar A are twice that of bar B. If the temperature of both bars is
increased by the same amount while preventing any expansion, then the ratio of
stress developed in bar A to that in bar B will be
(a) 2
(b) 4
(c) 8
(d) 16 (IES
1996)
Q.7. A steel bar, 300 mm long and 24 mm diameter, is turned down to
18 mm diameter for one third of its length. It is heated 300C above
room temperature, clamped at both ends and then allowed to cool to room
temperature. If the distance between the clamped is unchanged, the maximum
stress in the bar(a
= 12.5 x 10-6 per 0C and E = 200 GN/m2) is
(a) 25 MN/m2
(b) 50 MN/m2
(c) 75 MN/m2
(d) 100 MN/m2 (IES 2000)
Q.8. A railway track is laid so that there is no stress in the rails
at 100C. If there is no allowance for expansion then stress in the
rails at 600 C will be
(a) 53.3 N/mm2
(b) 110.7 N/mm2
(c) 115 N/mm2
(d) 120 N/mm2
Q.9. In the above problem if there is an expansion allowance of 10
mm per rail then stress in the rails at 600 will be
(a) 53.3 N/mm2
(b) 110.7 N/mm2
(c) 115 N/mm2
(d) 120 N/mm2
Q.10. In the above problem what will be expansion allowance if stress
induced is zero
(a) 1 mm
(b) 7 mm
(c) 11 mm
(d) 18 mm
Answers:
1. b
2. a
3. c
4. a
5. d
6. b
7. d
8. d
9. a
10. d
1. b
2. a
3. c
4. a
5. d
6. b
7. d
8. d
9. a
10. d
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