Download PTU (I.K.Gujral Punjab Technical University (IKGPTU)) B-Tech (Bachelor of Technology) (EEE)- Electrical And Electronics Engineering 2020 December 3rd Sem 76385 Engineering Mechanics Previous Question Paper
Total No. of Pages : 04
Total No. of Questions : 18
B.Tech. (EE / Electrical & Electronics Engg.) (2018 Batch)
B.Tech. (Electronics & Electrical Engg.) (2018 Batch) (Sem.?3)
ENGINEERING MECHANICS
Subject Code : BTXX-XXX-18
M.Code : 76385
Time : 3 Hrs. Max. Marks : 60
INST RUCT IONS T O CANDIDAT ES :
1 .
SECT ION-A is COMPULSORY cons is ting of TEN questions carrying TWO marks
each.
2 .
SECT ION-B c ontains F IVE questions c arrying FIVE marks eac h and s tud ents
have to atte mpt any FOUR q ues tions.
3 .
SECT ION-C contains THREE questions carrying T EN marks e ach and s tudents
have to atte mpt any T WO questio ns.
SECTION-A
Write briefly :
1.
Differentiate between symmetric and anti-symmetric tensors.
2.
Draw the free body diagram of roller support placed on horizontal plane.
3.
Write the parallel axis theorem and explain each of its term.
4.
Define angle of repose.
5.
Define principal moment of inertia.
6.
Write the relationship between loading and shear force in reference to beams.
7.
Write the torsion equation in its usual notations. Also explain each of them.
8.
Differentiate between 2-D and 3-D rotational motion.
9.
Define radius of gyration.
10. Explain general plane motion.
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SECTION-B
11. Three ropes are attached to the post at A (Fig. 1). The forces in the ropes are F1 = 260 N, F2
= 75 N, and F3 = 60 N. Determine the magnitude of the force R that is equivalent to the
three forces shown in the figure. 1
z
12 m
C
B
F2
3
4 m
m
F1
y
3 m
F3
A
x
FIG.1
12. Calculate the moment of inertia of the shaded area about the y-axis (Fig. 2) by using double
integration method.
y
y = h(x/b)2
h
x
b
FIG.2
13. Write the five terms acceleration formula in scalar and vector form. Explain each of its
terms briefly.
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14. Determine the smallest angle for which the slender bar (Fig. 3) can remain at rest. The
bar is homogeneous of weight W and length L. Neglect friction between the bar and wall at
B point.
B
L
A
u
s ? 0.5
FIG.3
15. In a pin jointed four bar mechanism, (Fig. 4), AB = 300 mm, BC = CD = 360 mm and AD =
600 mm. The angle BAD = 60?. The crank AB rotates uniformly at 100 rpm. Locate all
instantaneous centre and find angular velocity of the link BC.
C
360 mm
B
36
3
0
0
m
0
m
m
m
m
360 m60?
A
D
600 mm
FIG.4
SECTION-C
16. A solid steel shaft of 2 m length is to transmit 50 kW at 150 rpm. If the shear stress in the
shaft material is not to exceed 50 MPa and maximum allowable twist in the shaft is 1?,
calculate the safe shaft diameter. Assume G as 80 GPa.
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17. For the beam (Fig. 5), draw the shear force and bending moment diagrams. Neglect the
weight of the beam.
y
200 kN/m
A
x
C
B
2m
2m
FIG.5
18. The electric motor with an attached disk is running at a constant low speed of 120 rpm in
the direction as shown in Fig. 6. Its housing and mounting base are initially at rest. The
entire assembly is next set in rotation about the vertical Z-axis at the constant rate N = 60
rpm with a fixed angle = 30?. Determine : a) the angular velocity and angular acceleration
of the disk, b) the space and body cone, and c) the velocity and acceleration of point A at
the top of the disk for the instant shown in the figure 6.
x
z
A
z
y
C
0
O
OC = 250 mm
CA = 125 mm
N
FIG.6
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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This post was last modified on 13 February 2021