Indian Institute of Technology Madras (IIT-M) 2003 M.Tech Mechanical Engineering mechanical engg-gate - Question Paper

37. A truss consists of horizontal members (AC, CD, DB and EF) and vertical members (CE and
DE) having length one every. The members AE, DE and BF are inclined at 45° to the horizontal.
For the uniformly distributed load ‘p’ per unit length on the member EF of the truss shown in
figure provided below, the force in the member CD is
(a) (b p1
(c) 0
(d) A
38. A bullet of mass ‘m’ travels at a very high velocity v (as shown in the figure) and gets
embedded inside the block of mass ‘M’ initially at rest on a rough horizontal floor. The block
with the bullet is seen to move a distance ‘s’ along the floor. Assuming t to be the coefficient
to kinetic friction ranging from the block and the floor and ‘g’ the acceleration due to gravity what
is the velocity v of the bullet?
(a) g2pgs m
(b) M-m J2pgs F”
(d) L_J2pgs
39. A simply supported laterally loaded beam was obtained to deflect more than a specified
value. Which of the subsequent measures will decrease the deflection?
(a) Increase the area moment of inertia
(b) Increase the span of the beam
(c) choose a various material having lesser modulus of elasticity
(d) Magnitude of the load to be increased

40. A shaft subjected to torsion experiences a pure shear stress t on the surface. The
maximum principal stress on the surface, which is at 45° to the axis, will have a
value
(a) t cos 450
(c) t cos2 45°
(b) 2t cos 450
(d) 2t sin 45 cos 45°
41. For a certain engine having an avg. speed of 1200 rpm, a flywheel approximated as a
solid disc, is needed for keeping the fluctuation of speed within 2% about the avg. speed.
The fluctuation of kinetic energy per cycle is obtained to be 2k]. What is the lowest possible mass
of the flywheel if its diameter is
not exceed im?
(a) 40 kg (b) 51 kg (c) 62 kg (d) 73 kg
42. A flexible rotor-shaft system comprises of a 10 kg rotor disc placed in the middle of a
mass-less shaft of diameter 30 mm and length 500mm ranging from bearings (shaft is being taken
mass-less as the equivalent mass of the shaft is included in the rotor mass) mounted at the
ends. The bearings are presumed to simulate simply supported boundary conditions. The shaft

Earning:   Approval pending.