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S.No Question Option A Option B Option C Option D Answer Solution Comments Status Action
1 During a process on the closed system, its internal energy increases by twice the units than heat added to it. It is possible due to Radiation of heat from the surroundings Increasing of temperature Performing of shaft work on the system Performing of shaft work by the system c Comments Active
2 If hot water and cold water are mixed, then the entropy of the system will Increase Decrease Remains same May increase / decrease depending on initial temperature of hot water and cold water a \(ρ=\frac{P}{RT}\)
Density and Temperature are inversely related at constant Pressure.
Initially, hot water has a lower density and cold water has a higher density. Due to the density differences, hot water floats above cold water. Due to temperature differences heat transfer takes place within the mixture from hot water to cold water. Molecules of hot water start moving downwards and molecules of cold water start moving upwards as they lose and gain heat respectively. Thus, the mixture comes in motion as a result of buoyancy force originated from variation in fluid density. ∵ This motion increases the molecule's randomness and thus increases the entropy of the mixture.		 Comments Active
3 The door of a running refrigerator inside a room was left open. Which of the following statements is correct? The room will be cooled to the temperature inside the refrigerator The room will be cooled very slightly The room will be gradually warmed up The temperature of the air in room will remain unaffected c Comments Active
4 If a heat engine attains 100% thermal efficiency, it violates Zeroth law of thermodynamics First law of thermodynamics Second law of thermodynamics All of the above laws c Comments Active
5 Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant Pressure Temperature Volume Internal energy c Comments Active
6 2kg of substance receives 500KJ and undergoes a temperature change from 100C to 200C. The average specific heat of substance during the process will be \(°\) \(°\) 5 kJ/(kgK) \(°\) 2.5 kJ/(kgK) \(°\) 10 kJ/(kgK) \(°\) 25 kJ/(kgK) \(°\) b Given: m = 2 kg
Q = 500 KJ
T = 100 K \(∆\) \(°\)
Q = mcT \(∆\)
500 = 2C100 \(×\) \(×\)
C = 2.5kJ/(kgK) \(°\)		 Comments Active
7 In an isothermal process, the internal energy of gas molecules Increase Decrease Remains constant May increase/decrease depending on the properties of gas c Comments Active
8 A perfect gas at 27 is heated at constant pressure till its volume is double. The final temperature is \(℃\) 54 \(℃\) 327 \(℃\) 108 \(℃\) 600 \(℃\) b = \(\frac{V_{1}}{T_{1}}\) \(\frac{V_{2}}{T_{2}}\)
\(\frac{V}{300} = \frac{2V}{T_{2}}\)
T2 = 600 - 273 = 327 \(℃\)		 Comments Active
9 Which of the following is the property of a system? Pressure and temperature Internal energy Volume and density All of the above d Comments Active
10 According to which law, all perfect gases change in volume by 1/273th of their original volume at 0 for every 10 change in temperature when pressure remains constant \(℃\) \(℃\) Joule’s law Boyle’s law Gay-Lussac law Charles’s law d Comments Active
11 A thief stole a box full of jewellery of W kg and while carrying it on his head jumped down from third storey of the building. Before he reached the ground, he experienced a load of Zero Infinite Less than w Greater than w a
Considering a pseudo force which is an apparent force that acts on all masses whose motion is described using a non-inertial frame of reference, such as a rotating reference frame.
According to the problem
W – N = Fp
⇒ mg – N = mg
⇒ N = 0 ∴ No load is experienced by the man.		 Comments Active
12 A body moves, from rest with a constant acceleration of 5m per sec. The distance covered in 5sec is most nearly 38 m 62.5 m 966 m 124 m b S = ut + 1/2at2
= 0 + 1/22 \(×5×5\)
= 125/2 = 62.5		 Comments Active
13 A projectile is fired at an angle θ to the vertical. Its horizontal range will be maximum when θ is 30 \(°\) 45 \(°\) 60 \(°\) 90 \(°\) b Comments Active
14 Two forces each equal to P in magnitude act at right angles, their effect may be neutralized by a third force acting along their bisector in opposite direction whose magnitude is equal to 2P P/2 P \(2\) P/ \(2\) c A = B = P θ = 90°
Applying parallelogramm law
R = \(P^{2}+P^{2}\)
R = \(P2\)		 Comments Active
15 Which of the following is a vector quantity? Mass Momentum Angle Speed b Comments Active
16 Material best weldable with itself is Stainless steel Copper Aluminium Mild steel d Comments Active
17 Consumable electrodes are used in which of these welding process? TIG MIG Thermit Laser b Comments Active
18 The relationship between tool life (T) in minutes and cutting speed (V) in m/min is vnt=c vtn=c V/Tn=c Vn/T=c b Comments Active
19 Cold working process increase Impact strength Ductility Percentage of elongation Fatigue strength d In cold working process
1. No heating required.
2. The better surface finish obtained. Superior dimension control.
3. Better reproducibility and interchangeability of parts.
4. Improved strength properties like fatigue strength and tensile strength.		 Comments Active
20 Tool life in turning will decrease by maximum extent if we double the Depth of cut Feed Cutting velocity Tool rake angle c Tool life of any tool for any work material is governed by machining parameters mainly cutting velocity (V), feed, and depth of cut (t). 
Cutting velocity affects the maximum and depth of cut minimum. 
Most widely used tool life equation and expressed in equation form		 Comments Active
21 Material removal takes place in Abrasive jet Machining due to Electrochemical action Mechanical impact Fatigue failure of the material Sparking on impact b Comments Active
22 Cutting fluid is employed in machining for Cooling the tool and the job Lubricate at the rubbing surfaces Cleaning the machining zone All of the above d Comments Active
23 Curve generated by a fixed point on the circumference of a circle which rolls without slipping along a fixed straight line Involute Cycloid Spiral Helix b Comments Active
24 Conic section obtained by cutting a right circular cone by a section plane inclined to the axis of the cone and cutting all the generators Circle Ellipse Parabola Hyperbola b Comments Active
25 H7g6 is a Close running fit Push fit Shrink fit Press fit a
Comments Active
26 symbol in a drawing represents Perspective projection Third angle projection First angle projection Oblique projection c Comments Active
27 An Oldham coupling connects two shafts, when they are, Intersecting Parallel Coaxial Perpendicular b Comments Active
28 In the third angle projection, the object is imagined to be placed Below H.P. and behind V.P. Above H.P. and infront of V.P. Above H.P. and behind V.P. Below H.P. and infront of V.P. a The Third Angle Projection schema imagines the object in the third quadrant. One can place an object on the bottom of the horizontal plane and behind the vertical planes. Comments Active
29 A thin spherical shell of internal diameter d is subjected to an internal pressure p. If is the tensile stress for the shell material, then thickness of the shell (t) is equal to \(σ\) pd/2 \(σ\) pd/4 \(σ\) pd/ \(σ\) 4 pd2 \(σ\) b Comments Active
30 The shearing stress in a helical spring of wire diameter d and having mean diameter D, supporting a compressive load F is given by \(\frac{2FD}{Πd^{3}}×K\) \(\frac{4FD}{Πd^{3}}×K\) \(\frac{8FD}{Πd^{3}}×K\) \(\frac{16FD}{Πd^{3}}×K\) c Comments Active
31 Three different weights fall from a certain height under vacuum. They will take Same time to reach earth Times proportional to weight to reach Times inversely proportional to weight to reach earth Unpredictable b \(S=ut+\frac{1}{2}at^{2}\)
\(⇒t^{2}=\frac{2S}{g}(∵u=0 & a=g\)
\(⇒t=\frac{2S}{g}\)
∴ We can see that the time is independent of mass and thus all three will reach earth at the same time.		 Comments Active
32 Resilience of a material is important, when it is subjected to Thermal stresses Shock loading Fatigue Wear and tear b Comments Active
33 For a circular cross-section beam subjected to a shearing force F, the maximum shear F/d2 \(Ï€\) 4F/d2 \(Ï€\) 2F/d2 \(Ï€\) F/d2 \(4Ï€\) b Comments Active
34 For small discharge and high heads which pump is preferred Centrifugal type Reciprocating type Axial flow type Radial flow type b Comments Active
35 Francis turbine is best suited for Medium head application from 24 to 180m Low head installation up to 30m High head installation above 180m All types of heads a High head turbine: In this type of turbines, the net head varies from 150 m to 2000 m or even more, and these turbines require a small quantity of water. Example: Pelton wheel turbine.
Medium head turbine: The net head varies from 30 m to 150 m, and also these turbines require a moderate quantity of water. Example: Francis turbine.
Low head turbine: The net head is less than 30 m and also these turbines require a large quantity of water. Example: Kaplan turbine.		 Comments Active
36 For pump of same speed, discharge is proportional to Impeller diameter D2 D3 1/D3 c Comments Active
37 In a centrifugal pump, when the impeller speed is doubled, head developed becomes 2 times 1.414 times 4 times 1.5 times c Affinity law for pump
Head is directly proportional to square of speed
H N2 \(∝\)
\(\frac{H_{1}}{H_{2}}=(\frac{N_{1}}{N_{2}})^{2}\)
If N gets 2N
H’ = 4H		 Comments Active
38 According to plank’s law, the wavelength corresponding to the maximum energy is proportional to T T2 T3 1/T d Comments Active
39 A steam pipe is to be insulated by two insulating materials put over each other, for best results Better insulation should be put over pipe and inferior one over it. Inferior insulation should be put over pipe and better one over it. Both may be put in any order. Whether to put inferior one over pipe or the better one would depend on steam temperature. a Fourier’s law of conduction:
It states that the rate of heat transfer by conduction along a given direction is directly proportional to the temp gradient along that direction and is also directly proportional to the area of heat transfer lying perpendicular to the direction of heat transfer.		 Comments Active
40 Flow equation Q = ka(t1-t2)x, the term ‘x/(ka)’ is known as Thermal resistance Thermal coefficient Thermal conductivity Heat transfer coefficient a Comments Active
41 Which of the following has maximum value of thermal conductivity? Aluminium Steel Brass Copper d Comments Active
42 Heat flows from one body to other body when they have Different heat contents Different specific heats Different atomic structure Different temperatures d The heat will flow from the high-temperature region to the low-temperature region until the temperature distribution is the same throughout the body. Or, there may be a temperature gradient across an object. The heat will flow so as to equalize the temperature throughout the object. Comments Active
43 An odd shaped body weighing 7.5 kg and occupying 0.1m3 volume will be completely submerged in a fluid having specific gravity of 1 1.2 1.7 0.75 d Given m = 7.5 kgv = 0.1 m3
S = ?
gv = mg \(Ρ\)
g = = 750 \(Ρ\) \(\frac{7.5 × 10}{0.1}\)
S = = 0.75 \(\frac{750}{1000}\)		 Comments Active
44 A pressure of 25m of head of water is equal to 25 kN/m2 245 kN/m2 2500 kN/m2 2.5 kN/m2 b P = gh \(ρ\)
= 10009.8125 \(×\) \(×\)
= 245.25 KN/m2		 Comments Active
45 If mercury in a barometer is replaced by water, the height of 2cm of mercury will be following ……..cm of water 27.2 cm 50 cm 52 cm 13 cm a (gh)mercury = (gh)water \(ρ\) \(ρ\)
13600 2 = 1000 x \(×\) \(×\)
X = 136/5 = 27.2		 Comments Active
46 For a body floating in water, resultant pressure exerted by water acts at Bottom surface of body. Centroid of portion of body under water. All points on the surface of body Centroid of body b For a body floating in the liquid the normal pressure exerted by the liquid acts at all points on the surface of the body. Comments Active
47 An object having 10 kg mass weighs 5kg on a planet. The value of ‘g’ at this planet is 0.5 m/sec2 4.9 m/sec2 10.2 m/sec2 9.7 m/sec2 a As mass do not change with place but gravitation due to acceleration may change
Mg’ = 5
10 g’ = 5 \(×\)
G’ = 1/2 = 0.5m/s2		 Comments Active
48 A fluid is said to be ideal, is it is Incompressible Zero viscosity Viscous and incompressible Low density b Ideal fluid is incompressible, which means the density is constant. Ideal fluid is Ir-rotational, which means the flow is smooth, with no turbulence at all. Ideal fluid is also non-viscous, which means there is no friction. Comments Active
49 Surveying tapes are made of material having low coefficient of expansion and enough strength, The alloy used is Silver steel Hastelloy Monel metal Invar d Comments Active
50 The hardness number 1 of Mohr’s scale is assigned to Quartz Talc Topaz Diamond b Talc 1
Gypsum 2
Calcite 3
Fluorite 4
Apatite 5
Feldspar 6
Quartz 7
Topaz 8
Corundum 9
Diamond 10		 Comments Active
51 High speed steel (H.S.S.) belongs to the category of Medium-carbon steel High-carbon steel Alloy steel Stainless steel c Comments Active
52 Brass contains 70% copper and 30% zinc 70% copper and 30% tin 30% copper and 70% tin 60% copper and 40% tin a Comments Active
53 Which is false statement about tempering? Tempering is done to Improve machinability Improve ductility Release internal stresses Reduce hardness and brittleness a The aims of tempering are:
To relieve the internal stresses
To regulate the hardness and toughness
To decrease the brittleness
To restore some ductility
To induce shock resistance to Improving the toughness (strength)		 Comments Active
54 _______% of carbon in cast iron is <0.8% <1.3% >2% <6.3% c Comments Active
55 Ductility of a material can be defined as Ability to undergo large permanent deformation in compression Ability to recover its original form Ability to undergo large permanent deformations in tension All of the above c Comments Active
56 At the critical pressure ratio for a convergent nozzle, the velocity at outlet will be More than sonic velocity Less than sonic velocity Equal to sonic velocity None of the above a Mach number < 1 → subsonic velocity
Mach number = 1 → sonic velocity
Mach number > 1 → supersonic velocity
If a convergent nozzle is operating under choked condition, the exit Mach number is unity.		 Comments Active
57 The plant which is smaller in size and lower in weight for the same power, is Steam plant Gas turbine plant I.C. engine plant Diesel plant b Comments Active
58 Ideal air standard efficiency of a closed cycle gas turbine depends on Pressure ratio of the cycle only Temperature ratio of the cycle only Both the temperature ratio and pressure ratio None of the above a Case 1: If the working fluid is ideal then it depends on the Temperature ratio of the cycle.
\(η_{Brayton Cycle}=1-\frac{T_{min}}{T_{max}}\)
Case 2: If the working fluid is real then it depends on the Pressure ratio and index.
\(η_{Brayton Cycle}=1-\frac{1}{(r_{p})^{\frac{γ-1}{γ}}}\)		 Comments Active
59 For a two stage reciprocating air compressor, for minimum work required the intercooler pressure is given by P2 = \(P_{1}×P_{3}\) P2 = \(P_{1}×P_{3}\) P2 = 1/ \(P_{1}×P_{3}\) P2 = 1/ () \(P_{1}×P_{3}\) a Comments Active
60 For maximum efficiency in multi-stage compressor Air should be cooled to initial temperature between the stages Pressure ratio for each stage should be same Work done for each stage should be same All of the above d Comments Active