Mechanical Engineering Excerise 1
Transcript of Mechanical Engineering Excerise 1
Mechanical Engineering ‐ Excerise‐1
1. Given that the determinant of the matrix
1 3 02 6 41 0 2
⎡ ⎤⎢ ⎥⎢ ⎥⎢ ⎥−⎣ ⎦
is – 12, the determinant of
the matrix
2 6 04 12 82 0 4
⎡ ⎤⎢ ⎥⎢ ⎥⎢ ⎥−⎣ ⎦
is
(A) – 96 (B) –24 (C) 24 (D) 96
2. 0
sin1 cosx
x xLtx→
−−
is
(A) 0 (B) 1 (C) 3 (D) not defined
3. The argument of the complex number11
ii
+−
, where 1i = − , is
(A) – π (B) 2π
− (C) 2π (D) π
4. The matrix form of the linear system 3 5dx x ydt
= − and 4 8dy x ydt
= + is
(A) 3 54 8
x xdy ydt
−⎧ ⎫ ⎡ ⎤ ⎧ ⎫=⎨ ⎬ ⎨ ⎬⎢ ⎥
⎩ ⎭ ⎣ ⎦ ⎩ ⎭ (B)
3 84 5
x xdy ydt
⎧ ⎫ ⎡ ⎤ ⎧ ⎫=⎨ ⎬ ⎨ ⎬⎢ ⎥−⎩ ⎭ ⎣ ⎦ ⎩ ⎭
(C) 4 53 8
x xdy ydt
−⎧ ⎫ ⎡ ⎤ ⎧ ⎫=⎨ ⎬ ⎨ ⎬⎢ ⎥
⎩ ⎭ ⎣ ⎦ ⎩ ⎭ (D)
4 83 5
x xdy ydt
⎧ ⎫ ⎡ ⎤ ⎧ ⎫=⎨ ⎬ ⎨ ⎬⎢ ⎥−⎩ ⎭ ⎣ ⎦ ⎩ ⎭
5. Which one of the following describes the relationship among the three vectors,
, 2 3 and 5 6 4 ?i j k i j k i j k+ + + + + +
(A) The vectors are mutually perpendicular
(B) The vectors are linearly dependent
(C) The vectors are linearly independent
(D) The vectors are unit vectors
6. A circular rod of length ‘L’ and area of cross‐section ‘A’ has a modulus of elasticity
‘E’ and coefficient of thermal expansion ‘α’. One end of the rod is fixed and other
end is free. If the temperature of the rod is increased by ΔT, then
(A) stress developed in the rod is E α ΔT and strain developed in the rod is α ΔT
(B) both stress and strain developed in the rod are zero
(C) stress developed in the rod is zero and strain developed in the rod is α ΔT
(D) stress developed in the rod is E α ΔT and strain developed in the rod is zero
7. A metallic rod of 500 mm length and 50 mm diameter, when subjected to a tensile
force of 100 kN at the ends, experiences an increase in its length by 0.5 mm and a
reduction in its diameter by 0.015 mm. The Poisson’s ratio of the rod material is
_______
8. Critical damping is the
(A) Largest amount of damping for which no oscillation occurs in free vibration
(B) Smallest amount of damping for which no oscillation occurs in free vibration
(C) largest amount of damping for which the motion is simple harmonic in free
vibration
9
1
1
(D)
. A circ
cente
and t
(A) ze
(C) V
0. For th
I. Ma
II. A r
Indic
(A) B
(C) I i
1. A rig
figure
are g
Smallest
vibration
cular objec
er having v
the floor is
ero
opposite t
he given st
ating spur
revolute jo
ate the co
oth I and I
is false and
id link PQ
e. The mag
iven. The m
amount o
n
ct of radius
velocity V.
to the dire
tatements
gear teeth
oint is an ex
rrect answ
I are false
d II is true
is 2 m lon
gnitude an
magnitude
f damping
s r rolls wit
. The veloc
ction of m
:
h is an exam
xample of
wer.
(B) I is true
(D) Both I
ng and ori
nd directio
e of VP (in m
g for which
thout slipp
city at the
(
motion (
mple of hig
lower pair
e and II is f
and II are
ented at 2
n of veloc
m/s) at this
the motio
ping on a h
e point of
B) V in the
D) V vertic
gher pair
r
false
true
20o to the
ity VQ, and
s instant is
on is simple
orizontal l
contact be
e direction
cally upwar
e horizonta
d the direc
s
e harmoni
evel floor w
etween th
of motion
rd from th
al as show
ction of ve
c in free
with the
e object
e floor
wn in the
locity VP
1
1
1
1
(A) 2
2. Biot n
(A) co
(B) co
(C) in
(D) b
3. The m
with
(A) En
4. Cons
figure
The f
the c
at po
(A) 1
5. For a
‘B’, th
.14
number sig
onvective r
onductive
nertia force
uoyancy fo
maximum
a referenc
ntropy
ider a two
e below.
free stream
cylinder su
oint
complete
he conditio
(B) 1.8
gnifies the
resistance
resistance
e to viscou
orce to visc
theoretica
ce environm
(B) E
o‐dimensio
m velocity
rface temp
(B) 2
ly submerg
on of stabi
89
ratio of
in the fluid
in the soli
s force in t
cous force
al work obt
ment, is ca
Enthalpy
onal lamin
is U∞ and
perature T
ged body w
lity will be
(C) 1.21
d to condu
id to conve
the fluid
in the flui
tainable, w
alled
(C)
nar flow o
d the free
Ts. The loca
(C) 3
with centre
e
1
uctive resis
ective resis
d
when a sys
Exergy
over a long
stream te
al heat tran
e of gravity
(D) 0.96
stance in th
stance in t
tem intera
(D)
g cylinder
emperature
nsfer coeff
(D) 4
y ‘G’ and c
he solid
he fluid
acts to equ
) Rothalpy
r as shown
e T∞ is low
ficient is m
4
centre of b
uilibrium
n in the
wer than
minimum
uoyancy
(A) G is located below B (B) G is located above B
(C) G and B are coincident (D) independent of the locations of G and B
16. In a power plant, water (density = 1000 kg/m3) is pumped from 80 kPa to 3 MPa.
The pump has an isentropic efficiency of 0.85. Assuming that the temperature of
the water remains the same, the specific work (in kJ/kg) supplied to the pump is
(A) 0.34 (B) 2.48 (C) 2.92 (D) 3.43
17. Which one of the following is a CFC refrigerant?
(A) R744 (B) R290 (C) R502 (D) R718
18. The jobs arrive at a facility, for service, in a random manner. The probability
distribution of number of arrivals of jobs in a fixed time interval is
(A) Normal (B) Poisson (C) Erlang (D) Beta
19. In exponential smoothening method, which one of the following is true?
(A) 0 ≤ α ≤ 1 and high value of a is used for stable demand
(B) 0 ≤ α ≤ 1 and high value of a is used for unstable demand
(C) α ≥ 1 and high value of a is used for stable demand
(D) α ≤ 0 and high value of a is used for unstable demand
20. For machining a rectangular island represented by coordinates P(0,0), Q(100,0),
R(100,50) and S(0,50) on a casting using CNC milling machine, an end mill with a
diameter of 16 mm is used. The trajectory of the cutter centre to machine the
island PQRS is
(A) (‐8, ‐8), (108, ‐8), (108,58), (‐8,58) , (‐8, ‐8)
(B) (8,8), (94,8), (94,44), (8,44), (8,8)
(C) (‐8,8), (94,0), (94,44), (8,44), (‐8,8)
(D) (0,0), (100,0), (100,50), (50,0), (0,0)
21. Which one of the following instruments is widely used to check and calibrate
geometric features of machine tools during their assembly?
(A) Ultrasonic probe (B) Coordinate Measuring Machine (CMM)
(C) Laser interferometer (D) Vernier calipers
22. The major difficulty during welding of aluminium is due to its
(A) high tendency of oxidation (B) high thermal conductivity
(C) low melting point (D) low density
23. The main cutting force acting on a tool during the turning (orthogonal cutting)
operation of a metal is 400 N. The turning was performed using 2 mm depth of cut
and 0.1 mm/rev feed rate. The specific cutting pressure (in N/mm2) is
(A) 1000 (B) 2000 (C) 3000 (D) 4000
24. The process of reheating the martensitic steel to reduce its brittleness without any
significant loss in its hardness is
(A) normalising (B) annealing (C) quenching (D) tempering
25. In solid‐state welding, the contamination layers between the surfaces to be welded
are removed by
(A) alcohol (B) plastic deformation
(C) water jet (D) sand blasting
2
2
2
2
3
3
6. The i
coun
(A) 0
7. If y =
dydx
=
8. In th
dens
(A) 0
9. Using
subin
0. The s
The m
1. A blo
figure
coeff
need
integral ∫ter clockw
f(x) is the
2= at x = 1
e followin
ity. The sta
.18
g the trape
ntervals, th
state of str
maximum t
ock R of m
e. Block R
ficient of s
ed to mov
(C
ydx xd−
wise directio
(B)4π
−
solution o
10, f(15) =_
g table, x
andard dev
(B) 0.3
ezoidal rule
he definite
ress at a po
tensile stre
mass 100 k
is tied to
static frict
ve the bloc
)dy is eval
on. The int
4π
of 2
2 0d ydx
=
_______
is a discre
viation of x
36
e, and divi
integral 1
1
+
−∫
oint is give
ess (in MPa
kg is placed
the wall b
tion for al
k S is
luated alo
tegral is eq
(C) 2π
−
with the b
ete rando
x is
(C) 0.54
iding the i
1
1
| |x dx∫ is__
en by σx =
a) at the p
d on a blo
by a mass
l surfaces
ng the cir
qual to
boundary c
m variable
4
nterval of
______
‐6 MPa, σ
oint is____
ock S of m
less and in
is 0.4, th
rcle 2x y+
(D
conditions
e and p(x)
(D) 0.6
integratio
σy = 4 MPa,
____
mass 150 kg
nextensibl
e minimu
2 14
= trav
D) 4π
s y = 5 at x
is the pro
n into thre
, and τxy =
g as show
e string PQ
m force F
ersed in
= 0, and
obability
ee equal
‐8 MPa.
wn in the
Q. If the
F (in kN)
3
3
3
3
3
(A) 0
2. A pai
a spe
3. Cons
with
attac
_____
4. An id
norm
1000
5. A blo
and
horiz
veloc
6. A slid
a uni
partia
equa
.69
r of spur g
eed reduct
ider a can
length 0.0
ched at the
___
deal water
mal to its pa
kg/m3, the
ock weighin
kinetic fric
ontal forc
city (in m/s
der crank m
iform angu
ally balanc
l to crank
(B) 0.8
gears with
ion of 5:1.
ntilever be
01 m. The
e free tip,
r jet with v
ath and ex
e diamete
ng 200 N i
ction are
e (in new
s) of the bl
mechanism
ular velocit
ced by a r
radius. N
88
module 5
The numb
eam, havin
frequency
is 100 Hz
volume flo
xerts a forc
r (in mm) o
s in contac
0.4 and 0
ton) P = 1
ock attaine
m has slider
ty of 10 ra
revolving m
eglect the
(C) 0.98
mm and a
ber of teeth
ng negligib
y of vibrat
z. The flex
ow rate of
ce of 1000
of the wate
ct with a le
0.2, respec
10t, where
ed after 10
r mass of 1
ad/s. The p
mass of 6
e mass of
8
center dis
h on pinion
le mass a
tion of the
xural rigidi
f 0.05 m3/
N. Conside
er jet is __
evel plane
ctively. The
e t denote
0 seconds
10 kg, stro
primary ine
kg at the
connectin
(D) 1.37
stance of 4
n is ______
nd uniform
e beam, w
ty (in N.m
/s strikes a
ering the d
______
whose co
e block is
es the tim
is _______
ke of 0.2 m
ertia force
crank, pla
g rod and
450 mm is
__
m flexural
with a 0.5
m2) of the
a flat plate
density of w
oefficients
acted up
e in secon
_
m and rota
es of the sl
aced at a d
crank. W
used for
rigidity,
kg mass
beam is
e placed
water as
of static
on by a
nds. The
ates with
lider are
distance
When the
3
3
3
crank
norm
7. An o
Conv
The v
8. A rigi
= 2L/
frequ
(A)
9. A hyd
2000
20 µ
Somm
k angle (w
mal to the s
offset slid
ventionally
value of QR
id uniform
/3. Ends A
uency of th
2km
drodynam
rpm. Both
µm and b
merfeld nu
with respec
slider axis i
der‐crank
, the Quick
RR is _____
rod AB of
A and B ar
he system i
ic journal
h bearing b
earing is
umber of th
ct to slider
is _______
mechanis
k Return R
___
f length L a
e supporte
is given by
(B) km
bearing is
bore diam
lubricated
he bearing
r axis) is 3
_
sm is sho
Ratio (QRR)
and mass m
ed by spri
y
subject to
eter and le
d with an
g is ______
30°, the un
own in t
) is conside
m is hinged
ngs of spr
(C)
o 2000 N lo
ength are 4
n oil havin
__
nbalanced
the figure
ered to be
d at C such
ring consta
2km
oad at a ro
40 mm. If
ng viscosit
force (in n
e at an
greater th
h that AC =
ant k. The
(D)
otational s
radial clea
ty 0.03 P
newton)
instant.
han one.
= L/3, CB
e natural
5km
speed of
arance is
Pa.s, the
4
4
4
0. A 20
immo
the Y
/°C, r
the ro
1. 1.5 k
kJ/kg
temp
3277
2. Cons
figure
const
is rem
coeff
00 mm lo
ovable rigi
Young’s mo
respective
od is _____
g of water
g, hf = 50
perature o
.0 kJ/kg). T
ider one d
e below) o
tant heat f
moved fro
ficient of 2
ng, stress
d walls. Th
odulus and
ly, the ma
___
r is in satu
05 kJ/kg).
of water re
The heat a
dimensiona
of thicknes
flux, q" = 1
om the wa
50 W/m2.K
s free rod
he temper
d coefficien
agnitude o
rated liqui
Heat is a
eaches 40
dded (in kJ
al steady s
ss 30 mm
1 × 105 W/m
all by conv
K. The tem
d at room
rature of th
nt of therm
of the long
d state at
added in
00°C (v =
J) in the pr
state heat
and therm
m2 is appli
vection w
mperature (
m tempera
he rod is u
mal expans
gitudinal st
2 bar (vf =
a constan
1.5493 m3
rocess is __
conductio
mal conduc
ed. On the
ith a fluid
(in °C), at x
ture is he
uniformly r
sion are 20
tress (in M
= 0.001061
nt pressure3/kg, u =
______
n across a
ctivity 15 W
e other sid
d at 25°C
x = 0 is____
eld betwe
raised by 2
00 GPa and
MPa) deve
1 m3/kg, uf
e process
2967.0 kJ/
wall (as s
W/m.K. At
e of the w
and heat
____
een two
250°C. If
d 1× 10‐5
loped in
f = 504.0
till the
/kg, h =
hown in
x = 0, a
wall, heat
transfer
43. Water flows through a pipe having an inner radius of 10 mm at the rate of 36 kg/hr
at 25°C. The viscosity of water at 25°C is 0.001 kg/m.s. The Reynolds number of the
flow is_______
44. For a fully developed flow of water in a pipe having diameter 10 cm, velocity 0.1
m/s and kinematic viscosity 10‐5 m2/s, the value of Darcy friction factor is_______
45. In a simple concentric shaft‐bearing arrangement, the lubricant flows in the 2 mm
gap between the shaft and the bearing. The flow may be assumed to be a plane
Couette flow with zero pressure gradient. The diameter of the shaft is 100 mm and
its tangential speed is 10 m/s. The dynamic viscosity of the lubricant is 0.1 kg/m.s.
The frictional resisting force (in newton) per 100 mm length of the bearing is
_______
46. The non‐dimensional fluid temperature profile near the surface of a convectively
cooled flat plate is given by2
W
W
T T y ya b cT T L L∞
− ⎛ ⎞= + + ⎜ ⎟− ⎝ ⎠, where y is measured
perpendicular to the plate, L is the plate length, and a, b and c are arbitrary
constants. TW and T∞ are wall and ambient temperatures, respectively. If the
thermal conductivity of the fluid is k and the wall heat flux is q", the Nusselt
number "
W
q LNuT T k∞
=−
. is equal to
(A) a (B) b (C) 2c (D) (b + 2c)
47. In an air‐standard Otto cycle, air is supplied at 0.1 MPa and 308 K. The ratio of the
specific heats (γ) and the specific gas constant (R) of air are 1.4 and 288.8 J/kg.K,
respectively. If the compression ratio is 8 and the maximum temperature in the
cycle is 2660 K, the heat (in kJ/kg) supplied to the engine is _______
4
4
5
5
8. A rev
certa
reser
(A) 0
9. An id
MPa,
both
high
entha
for re
Disre
0. Jobs
jobs f
40 m
at the
(A) 57
1. A me
rod a
minu
versible he
ain amoun
rvoir at 400
.8
deal reheat
, with rehe
turbines i
pressure
alpy of wa
elevant dat
egarding th
arrive at a
follows Po
minutes. Th
e facility p
57
etal rod of
at any insta
utes. The tr
eat engine
t of heat
0 K. The ne
(B) 1.0
t Rankine c
eat being d
is 500°C a
turbine an
ater at the
ta.
he pump w
a facility at
oisson distr
he service
er shift wil
(B) 143
initial leng
ant is given
rue strain r
e receives
from a re
et work ou
0
cycle opera
done at 4
nd the ent
nd 2247 k
exit from
work, the cy
t an averag
ribution. T
time follow
ll be
4
gth L0 is su
n by the e
rate (in mi
2 kJ of he
eservoir a
tput (in kJ
(C) 1.4
ates betwe
MPa. The
thalpy of s
kJ/kg at th
the pump
ycle efficie
ge rate of
he average
ws expone
(C) 75
ubjected to
xpression,
n‐1) at the
eat from a
t 800 K. I
) of the cyc
een the pre
temperatu
steam is 3
he exit of
p is 191 kJ
ncy (in per
5 in an 8 h
e service ti
ential distr
o a drawin
L(t) = L0(1
end of one
a reservoir
It rejects
cle is
(D) 2.0
essure lim
ure of stea
3185 kJ/kg
f low pres
/kg. Use t
rcentage) i
hour shift.
ime of a jo
ribution. Id
(D) 103
g process.
1 + t2), whe
e minute is
r at 1000
1 kJ of he
its of 10 kP
am at the
at the ex
sure turbi
he followi
is _______
The arriva
ob on the f
dle time (in
The lengt
ere t is the
s _______
K and a
eat to a
Pa and 8
inlets of
it of the
ine. The
ng table
_
al of the
facility is
n hours)
th of the
e time in
5
5
5
5
2. Durin
that
degre
opera
3. For th
(A) P‐
(C) P‐
4. If the
the to
5. An a
hole
core
_____
ng pure or
the thickn
ee rake a
ation is ___
he given as
‐I, Q‐III, R‐
‐II, Q‐III, R‐
e Taylor’s t
ool life (in
luminium
of 100 mm
(density 16
_________
rthogonal t
ness of th
ngle tool
_____
ssembly: 2
IV, S‐II
‐IV, S‐I
ool life exp
min) for m
alloy (den
m diamete
600 kg/m3
_____
turning op
e chip pro
is 0.2 m
25 H7/g8, m
ponent n is
maximum p
nsity 2600
er and 100
). The net
peration of
oduced is
m/rev. Th
match Gro
(B) P‐I,
(D) P‐II,
s 0.2, and t
production
kg/m3) ca
0 mm leng
buoyancy
f a hollow
0.5 mm. T
he shear s
up A with
Q‐IV, R‐III,
, Q‐IV, R‐III
the tool ch
n rate is ___
asting is to
gth is mad
force (in n
w cylindrica
The feed
strain prod
Group B
S‐II
I, S‐I
hanging tim
______
o be produ
de in the c
newton) ac
al pipe, it
given to t
duced dur
me is 1.5 m
uced. A cy
casting usi
cting on th
is found
the zero
ring the
min, then
ylindrical
ing sand
e core is
Key for Excerise‐1
Q.NO Key/ Range
1 A
2 A
3 C
4 A
5 B
6 C
7 0.29 to 0.31
8 B
9 A
10 D
11 D
12 B
13 C
14 B
15 A
16 D
17 C
18 B
19 B
20 A
21 C
22 A
23 B
24 A
25 B
26 C
27 34 to 36
28 D
29 1.10 to 1.12
30 8.4 to 8.5
31 D
32 29 to 31
33 0.064 to 0.067
34 56 to 57
35 4.8 to 5.0
36 29 to 31
37 1.2 to 1.3
38 D
39 0.75 to 0.85
40 499 to 501
41 4155 to 4160
42 620 to 630
43 635 to 638
44 0.06 to 0.07
45 15 to 16
46 B
47 1400 to 1420
48 C
49 40 to 42 50 B 51 0.9 to 1.1 52 2.8 to 3.0 53 D 54 5.9 to 6.1 55 7 to 8