DipIETE
– ET (OLD SCHEME)
Code: DE02 Subject:
APPLIED MECHANICS
Time: 3 Hours
Max. Marks: 100
NOTE: There are 9 Questions in all.
· Question 1 is
compulsory and carries 20 marks. Answer to Q.1 must be written in the space
provided for it in the answer book supplied and nowhere else.
· Out of the
remaining EIGHT Questions, answer any FIVE Questions. Each question carries 16
marks.
· Any required data
not explicitly given, may be suitably assumed and stated.
Q.1 Choose the correct or the best alternative in the following: (2
10)
a.
Which of the following is not considered as the basic quantity?
(A)
Length (B)
Mass
(C)
Time (D)
Density
b. The vectors are said to be equal if they have____________.
(A)
same magnitude
(B) same magnitude, same direction
(C) same magnitude, different direction
(D)
different
magnitude, same direction
c.
(A)
Work (B) Force
(C) Inertia (D)
Energy
d. A force which combines with two or more
forces to produce equilibrium is called?
(A) resultant (B) equilibrium
(C)
couple (D)
moment
e. The time-acceleration graph of a body moving
with uniform acceleration is a straight line ___________.
(A) passing through the origin. (B)
inclined to the time axis.
(C)
parallel to time axis. (D) parallel
to acceleration axis.
f. A body has linear momentum P and translational
kinetic energy E. If momentum becomes 2P, the K.E. will have the value
__________.
(A) 0.5E (B) E
(C) 2E (D) 4E
g. The apparent weight of a man in a lift is
less than the real weight when the lift is going down ________.
(A) freely (B) under the force of gravity
(C) with some constant velocity (D) with some acceleration
h. In SHM, the acceleration is proportional to
_________.
(A) displacement (B) linear velocity
(C) time (D) rate
of change of angular velocity
i. A
zero torque acting on a system will result in conservation of _________.
(A)
linear velocity (B)
angular velocity
(C) angular momentum (D) moment of momentum
j. A
solid particle covers equal distances around a circular path in equal intervals
of time. Which of the following parameters connected with the motion of
particle remains constant with time?
(A) displacement (B) speed
(C) velocity (D)
acceleration
Answer any FIVE
Questions out of EIGHT Questions.
Each question
carries 16 marks.
Q.2 a. Explain difference between fundamental &
derived units. Which system of units is being followed in
b. Find the greatest and the least resultant of
two forces whose magnitudes are 50 N and 30 N respectively by making the suitable
assumptions in respect of their angle of inclination. (10)
Q.3 a. Describe the method of finding centre of
gravity of an irregular body. (6)
b. Determine the position of the centroid of the section shown in Fig.1. (10)
Q.4 a. Define:
(i) Coefficient of friction
(ii) Angle of friction
(iii) Angle of repose (6)
b. A
block of wood weighs 25 N. It can be just drawn along a table by a horizontal
force of 15 N, Find: (10)
(i)
Co-efficient of friction,
(ii) If the block is then loaded with another 10 N
load, which least force would
be able to move the
block?
Q.5 a. State
and explain D’Alembert’s principle. (6)
b. A
bullet weighing 2 N leaves the barrel of a gun with a velocity of 25 m/s. Find
the impulse of force produced by the discharge of bullet when the force lasted
for 0.2 s. Also find the average impulsive force. (10)
Q.6 a. What
do you understand by a self locking machine? State the condition for self
locking. (4)
b. The
length of an inclined plane is 5 m. and its height is 2.5 m. If a force of 400
N pulls a load of 600 N up the inclined plane, find: (6)
(i) Mechanical
advantage;
(ii) Velocity Ratio; and
(iii) Efficiency of the
machine.
c. State
Lami’s theorem. What are the conditions of equilibrium of system of coplanar
forces? (6)
Q.7 a. Define: (6)
(i) Hooke’s law.
(ii)
Modulus of rigidity.
(iii) Bulk
modulus of elasticity.
b. The
following observations were made during a tensile test on a mild steel specimen
40 mm diameter and 200 mm long. Elongation with 40 kN load (within limit of
proportionality), δl =0.0304 mm, Yield load = 161 kN, maximum load = 242
kN, Length of specimen at fracture = 249 mm. (10)
Determine:
(i) Young's modulus of elasticity.
(ii) Yield
point stress.
(iii) Ultimate stress.
(iv) Percentage
elongation.
Q.8 a. What
assumptions are made while deriving the torsion equation? (6)
b. A solid steel shaft is subjected to a torque of
45 kNm. If the angle of twist is 0.5° per metre length of the shaft and the
shear stress is not to be allowed to exceed 90 MN/m2 find: (10)
(i) Suitable diameter
for the shaft
(ii) Final maximum shear stress and angle of twist;
and
(iii) Maximum shear strain in the shaft. Take: C = 80
GN/m2
Q.9 a. Define Shear force and Bending moment
diagrams. What are their salient features? (6)
b. A
simply supported beam is carrying a u.d.l. of 2.5 kN/m over the right half
portion of the beam. The length of the beam is 6 m. draw the S.F.D. and B.M.D. for the beam. (10)
