Jadavpur University 2007 B.E Mechanical Engineering STOF MATARIALS - exam paper

EX/ML 12D/75/2006
FIRST ENGINEERING MECHANICAL EXAMINATION, 2006
(2nd Semester)
Strength of Materials
Full Marks : 100
Time : 3 (3) Hrs.
Verify this ques. booklet contains 5 (5) pages & 7 (7) ques..
ans various parts of the identical ques. strictly in the identical place. You may
leave blank space if you do not want to ans any question(s). Do not attempt
more than 5 (5) ques. as per the instruction provided beneath. All ques.
carry equal marks.
ans ques. no. one & any 4 (4) from the rest
1. Identify the accurate ans (any ten) [Answers must be supported by relevant
equations or computations whenever needed.]
i) If a closed coiled helical spring is cut into halves, then the stiffness of the cut coils
will be
(a) Double (b) Half (c) identical (d) None
ii) If the modulus of elasticity is equal to zero, the material is stated to be
(a) Rigid (b) Plastic (c) Flexible (d) Prismatic
iii) In case of a triangular cross-section, maximum shear stress occurs at
(a) The neutral axis (b) Half the height (c) 1/3 of the height (d) None
iv) Principal plane of stress is that plane on which the resulting stress is
(a) tangential (b) Normal (c) Shear (d) None
v) In thin cylindrical and spherical shells the variations of hoop and longitudinal stress
from the inner radius to the outer radius are
(a) Constant (b) Linear (c) Logarithmic (d) None
vi) Torque which produces a twist of one radian on a shaft of unit length is called
(a) Maximum torque (b) Minimum torque (c) Torsional Rigidity (d) Modulus
of Rupture
vii) If the maximum and minimum principal stresses in a stressed body are 100 N/mm2
and 50 N/mm2 , the Mohr’s stress circle radius in consistent unit will be
(a) –50 (b) 25 (c) 75 (d) –25
viii) The columns with both ends fixed can withstand a crippling load as compared to
one with hinged ends
1
(a) More (b) Less (c) Equal (d) None
ix) The maximum deflection of a cantilever beam of length L with single concentrated
load P at its free end is:
(a) PL3/EI (b) PL2/EI (c) PL/3EI (d) PL3/EI
x) Maximum slope in a cantilever beam occurs at its
(a) Free end (b) Fixed end (c) Mid point (d) None

Earning:   Approval pending.