| Post Name | LECTURER IN MECHANICAL ENGINEERING (POLYTECHNICS) |
|---|---|
| Department | TECHNICAL EDUCATION |
| Question Paper Code | 003/2014 |
| Date of Test | 9 January 2014 |
| Medium of Question | ENGLISH |
| Exam Type | OMR Examination |
| Total Questions | 100 |
1
For a viscous flow, the relation between the coefficient of friction f and Reynolds number Re is:
Answer
Question Cancelled
2
For flow through pipes, the maximum transmission efficiency that can achieve is :
Answer
A. 100%
3
The unit of Chezy's constant C in Chezy's formula is:
Answer
D. m¹⁄²/s
4
The ratio of the pitch diameter of Pelton wheel to the diameter of the jet is called :
Answer
A. Jet ratio
5
The hydraulic efficiency of a turbine with mean bucket diameter 1 m and running at
1000 rpm with net head 700 m when the side clearance angle is 15 degree and discharge of
100 liters/s is :
Answer
D. 97%
6
The specific speed of a Francis turbine which develops 7225 kW power under a head of 25
meters at 135 r.p.m 18 :
Answer
Question Cancelled
7
The head loss due to friction for the flow of water through penstocks can be minimized by :
Answer
B. Increasing the diameter of penstock
8
The head against which the centrifugal pump has to work is called : se fl
Answer
D. Manometric head
9
An example of a turbine with high head and low specific apeed ia:
Answer
C. Pelton
10
The slip of a single acting reciprocating pump, running at 50 rpm, delivers 100 liters/s when the diameter of piston and stroke length are 200 mm and 400 mm respectively is:
Answer
Question Cancelled
11
Inthe Van der Wall's equation (p+
Answer
D. None
12
Which parameter remaine constant during Joule-Thomson expansion?
Answer
C. Enthalpy
13
For an ideal gas the compressibility factor is :
Answer
B. Unity |
14
A heat pump works on reversed Carnot cycle has a COP of 5. If it works as a refrigerator
taking 1 kW of work input, the refrigerator effect will be : |
Answer
D. 4kW
15
The value of Univereal gas constant 18 : ;
Answer
D. None
16
Which one of the following is the extensive property of the system?
Answer
A. Volume
17
Which parameter remains constant during a reversible adiabatic process?
Answer
C. Entropy
18
Second law of thermodynamics defines °
Answer
D. Entropy
19
Which one of the following relation defines Helmholtz function F?
Answer
D. U-TS
20
Which one of the following parameters is significant to ascertain chemical equilibrium of a
system?
Answer
D. Gibbs Function
21
Which of the following cast iron consists of carbon in rosette form?
Answer
C. Malleable cast iron
22
Puddling is the process employed for converting -
Answer
B. Pig iron mto wrought iron
23
The melting point of mild steel in degree centigrade is about :
Answer
D. 1500
24
Which is the magnetic allotrope of iron?
Answer
A. @ iron
25
Austempering is a heat treatment process used to obtain greater :
Answer
Question Cancelled
26
18/8 stainless steel contains :- z?
Answer
B. 18% Chromium, 8% Nickel :
27
Muntz metal contains copper and:-zinc in the ratio :
Answer
C. 222
28
Monal metal is an alloy of :
Answer
A. Nickel and Copper
29
The hardness of a lathe bed material should be measured by :
Answer
B. Brinell Hardness tester
30
White metal is an alloy of lead with :
Answer
C. Tin
31
The forging of steel specimen is done at a temperature of :
Answer
Question Cancelled
32
Which one of the following is not an application of forging?
Answer
D. Steel balls of ball bearing
33
The process of removing the burns or flash from a forged component in drop forging is called :
Answer
C. Trimming
34
The electric resistance welding operates with :
Answer
B. High current and low voltage
35
Spot welding, projection welding and seam welding belong to the category of :
Answer
D. Resistance welding
36
The number of zones of heat generation in spot welding are :
Answer
C. 5
37
Which one of the following is not a fusion welding process?
Answer
Question Cancelled
38
The ratio between oxygen and acetylene gases for neutral flame in gas welding is :
Answer
B. 1 : 1
39
Thermit, used in thermit welding process is a mixture of :
Answer
B. Aluminium and Iron Oxide
40
The temperature developed during a thermit welding process is in the order of :
Answer
C. 2500°C
41
The current value in the arc welding is decided by :
Answer
Question Cancelled
42
Weld pool
Select the correct answer using the code given below
Answer
Question Cancelled
43
‘The straight polarity in ac arc welding is recommended for welding :
Answer
Question Cancelled
44
Which of the following welding methods uses pool of molten metal?
Answer
A. Submerged arc welding
45
The welding zone in the TIG are welding is shielded by an atmesphere of : 44%,
Answer
D. Helium
46
Which of the following welding techniques uses a non consumable electrode?
Answer
B. TIG
47
47.. Vacuum environment is required in: se
Answer
C. Electron beam welding
48
High speed electron beam of electron beam welding is focused on the weld spot using :
Answer
D. Magnetic lens
49
Grey iron is usually welded using the following method :
Answer
Question Cancelled
50
Weld spatter is: |
Answer
A. a welding defect
51
All of the following are units of thermal conductivity except ;
Answer
C. Wim-s-k ;
52
A compesite wall of a furnace has two layers of equal thickness with thermal conductivities :
in the ratio 3: 2, What is the ratio of temperature drop across the two layers :
Answer
A. 2:3
53
Critical thickness of insulation for a sphere with thermal conductivity k and convective heat |
transfer coefficient h is given by : |
Answer
A. 2k/h
54
For a perfectly black body:
Answer
A. Absorptivity α = 1, Reflectivity ρ = 0 and transmissivity τ = 0
55
The intensity of solar radiation on earth is:
Answer
B. 1kW/m?
56
If the temperature of a hot body is increased by 50% the amount of radiation emitted by it
would increage by nearly :
Answer
D. 500%
57
The value of shape factor for two infinite parallel planes separated by a distance x is :
Answer
B. 1
58
The ratio of heat transfer by convection to that by conduction is called :
Answer
B. Nusselt Number
59
Which dimensionless number has a significant role in natural convection?
Answer
A. Grashoff Number
60
For the same operating temperature limits the COP of the heat pump equals :
Answer
B. 1+ COP of Refrigerator
61
A Carnot refrigerator rejects 3000 kJ of heat at 400 K while using 1000 kJ of work. The
lowest operating temperature in the cycle should be about :
Answer
C. 267K
62
The refrigeration system of a passenger aircraft works on reversed : pile hy;
Answer
A. Brayton Cycle
63
During which component of vapour compression refrigeration system, the enthalpy remains
Constant :
Answer
C. Throttle Valve
64
One tone of refrigeration is equal to:
Answer
A. 3.5 kW
65
The ignition temperature of diesel is about :
Answer
B. 400°C
66
Knocking tendency in SI engine reduces with increasing :
Answer
C. Engine Speed
67
The two reference fuels used for cetane rating are :
Answer
C. Cetane and alpha methyl naphthalene
68
For a two stage reciprocating air compressor with perfect inter cooling the work input will be minimum if the supply pressure P₁, the intercooler pressure P₂ and the delivery pressure P₃ are related as:
Answer
A. P₂ = (P₁ × P₃)⁰·⁵
69
Optimum pressure ratio for maximum specific output for ideal gas turbine power plant ’
operating at initial temperature of 300 K and the maximum temperature of 1000 K is closer
to :
,
Answer
B. 8
70
ee 70. The use of regeneration in a gas turbine cycle increases :
Answer
A. Efficiency but has no effect on output
71
Which one of the following is a lower pair? |
Answer
C. Shaft in a bearing
72
The average tensions on the tight and slack side of a flat belt drive system are 700 N and 400 N respectively. If the linear velocity of the belt is 5 m/s, the power transmitted by the belt drive system will be:
Answer
A. 1.5 kW
73
Ina6 x 20 wire rope, number 6 indicates :
Answer
B. Number of strands in the wire rope
74
The motion transmitted between the teeth of two spur gears is generally :
Answer
D. Partly sliding and partly rolling
75
The product of circular pitch and diametral pitch equals :
Answer
A. z
76
In a flat belt drive, the belt can be subjected to maximum tension T and a centrifugal tension T꜀. For maximum power transmission:
Answer
C. T = 3T꜀
77
Which of the following is not a common section of V belts? ഷു “
Answer
A. F
78
Arack is a gear of infinite :
Answer
C. Diameter
79
The circular pitch of a toothed wheel with 24 teeth and a module of 4.25 mm is:
Answer
D. 13.35 mm
80
The maximum efficiency of a worm and worm wheel system in terms of friction angle ® is :
Answer
C. 1—sind/] + ഥന
81
Ina multiple disc clutch, nl and n2 are the number of discs on the driving and driven shafts
respectively. Then the number of pairs of contact surface 18 :
Answer
B. nlt+n2—1
82
The type of brakes commonly used in automobiles is :
Answer
A. Shoe brake
83
A reverted gear train is one in which the output and input shaft :
Answer
B. Are coaxial
84
Which of the following is not a common section of V belts?
Answer
Question Cancelled
85
When two spur gears having involute profiles on their teeth engage the line of action is
tangential to:
Answer
D. Base circle
3/2014 12 A
86
A reverted gear train is one in which the output and input shaft :
Answer
B. Are coaxial
(൧) Are at right angles to each other
87
17 86. AGO mm long and 6 mm thick fillet weld carries a steady load of 15 kN along the weld, The
ahear strength of the weld material is 200 MPa. The factor of safety is :
Answer
C. 4.8
88
Acircular solid rod of diameter d welded to a right flat plate by a circular fillet weld of throat
thickness t is subject to a twisting moment T. The maximum shear stress induced in the weld:
18°
Answer
B. 27 / atd® i
89
The efficiency of a power screw is maximum when the lead angle in terms of friction angle Φ is:
Answer
Question Cancelled
90
Ina BSW thread the. angle between the flanks is :
Answer
C. 65°
91
A high pressure angle for spur gears leads to :
Answer
B. Wide base and stronger teeth |
92
A worm has a lead angle of 22.5°. This corresponds to a helix angle of : |
Answer
D. 67.5° |
93
Which type of spring is usually used for an automobile clutch?
Answer
D. None
94
The ratio between the mean diameter of the coil and diameter of wire is called :
Answer
D. Spring index,
95
A spring with spring constant s has been cut into n equal parts. Each portion of the cut spring will have a spring constant equal to:
Answer
D. ns
96
Which of the following is not a friction clutch?
Answer
B. Jaw clutch
97
The maximum stress induced in a spiral spring in terms of Moment applied M, breadth of
strip b and thickness of strip t is:
Answer
A. 12M/bt?
98
In design of helical springs the spring index is usually taken as :
Answer
A. 8
99
The stress induced in the circular section wire of a closed coil helical spring in terms of axial
load W, mean coil diameter D and wire diameter d is :
Answer
A. 8WD/ad*
100
Spring stiffness is :
Answer
A. Load per unit deflection
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