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S.No Question Option A Option B Option C Option D Answer Solution Comments Status Action
1 In dry sump lubricating system the capacity of the oil pressure pump compared to oil scavenging pump is always: Lesser May be lesser or greater same Greater a A dry sump lubricating system is used for the supply of oil and is carried out in an external tank.
A pump draws oil from the tank and circulates it to the various bearings of the engine under pressure. Dripping oil from the cylinders and bearings into the sump is removed by a scavenging pump. So, oil is prevented from accumulating from the base of the engine.
The capacity of the oil pump is always less than the scavenging pump. A filter with a bypass valve is placed in between the supply tank and scavenge pump in the system. The pressure relief valve opens permitting oil to bypass the filter and reach the supply tank when the filter is clogged.
To remove heat from the oil, separate the oil cooler with either water or air as the cooling medium is provided in the dry – sump system.		 Comments Active
2 A 100 N force acts from a point P(0,0,0) to a point Q(1,1,1); then the force in N, is represented as: ()++) \(\frac{100}{2}\) \((i\) \(j\) \(k\) ()++) \(\frac{100}{3}\) \((i\) \(j\) \(k\) 100 100++) \((i\) \(j\) \(k\) b Force, F = 100 N, P(0,0,0), and Q(1,1,1)
Then, the unit vector along PQ, \(PQ=\frac{PQ}{(PQ )}=\frac{i+j+k}{1^{2}+1^{2}+1^{2}}=\frac{i+j+k}{3}\)
Force along \(PQ=F×PQ=100×\frac{i+j+k}{3}\)		 Comments Active
3 The force behind the existence of surface tension is: compressive cohesion adhesion tension b • Cohesion: The force of attraction between the molecules of a liquid by virtue of which they are bound to each other to remain as one assemblage of particles is known as the force of cohesion.
• Adhesion: The force of attraction between unlike molecules, i.e. between the molecules of different liquids or between the molecules of a liquid and those of a solid body when they are in contact with each other, is known as the force of adhesion. This force enables two different liquids to adhere to each other or a liquid to adhere to a solid body or surface.
• Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible. It occurs at the interface of two liquids, due to the intermolecular force of cohesion. This property enables the liquid to resist tensile stress.
• Compressibility is the ability of fluid to change its volume under pressure.		 Comments Active
4 In variable flow process any thermodynamic property will have a fixed value at a particular location and will change with time any thermodynamic property will have varying values at a particular location and will not change with time any thermodynamic property will have varying values at a particular location and will also change with time any thermodynamic property will have a fixed value at a particular location and will not change with time a In a variable flow process (also called a transient flow process), the thermodynamic properties at a particular location in the system do not remain constant but change with time. This means that any property such as pressure, temperature, or velocity will have a specific value at a given point, but this value varies as time progresses. This contrasts with a steady flow process, where properties at any location remain constant over time. Comments Active
5 What will be the pressure at point B of this U-tube manometer? Take ₁ = density of light liquid and 2 = density of heavy liquid. \(ρ\) \(ρ\)
 (1gh1 - 2gh2) \(ρ\) \(ρ\) -(1gh1 + 2gh2) \(ρ\) \(ρ\) (1gh1+2gh2) \(ρ\) \(ρ\) (1gh1-2gh₂) \(ρ\) \(ρ\) b In this problem , the pressure at point B is:

Pressure of liquid above A-A in right column = 0
Pressure of liquid above A-A in left column = PB + \(ρ_{1}gh_{1}+ρ_{2}gh_{2}\)
Equating both the pressure, we get:
\(P_{B}+ρ_{1}gh_{1}+ ρ_{2}gh_{2}=0\)
) \(P_{B}=-(ρ_{1}gh_{1}+ρ_{2}gh_{2}\)		 Comments Active
6 Entropy of a system always decreases may increase or decrease increases only when friction takes place always increases b Entropy is a measure of the disorder or randomness of a system.
For a reversible process, entropy can remain constant or change depending on the process (it may increase or decrease).
For an irreversible process, entropy of the system and surroundings combined always increases.
The entropy of an isolated system never decreases; it either remains constant (ideal reversible process) or increases (irreversible process).		 Comments Active
7 For an incompressible fluid, the discharge is usually expressed as the: weight per second of the fluid density difference of the fluid mass flow rate of the fluid volume flow rate of the fluid d For incompressible fluids (like water), the density remains constant. Therefore, discharge is typically expressed as the volume flow rate, which is the volume of fluid flowing per unit time (e.g., cubic meters per second).
Discharge, \(Q=AV=mv(m^{3}/s)\)		 Comments Active
8 If the sum of whirl components of velocity at inlet and outlet of a DE level turbine is found to be 1200 m/s and mass flow rate of steam is 15 kg/minute, then tangential force on the blade is: 28 KN 400 N 300 N 18 KN c \(Vw_{1}+Vw_{2}=1200 m/s\)
\(m=15Kg/min\)
From Newton’s 2nd law of motion.
Tangential force, \(F_{t}=mass ×tangential acceleration \)
\(=mass flow rate×change in velocity\)
\(F_{t}=m(Vw_{1}+Vw_{2})\)
\(F_{t}=\frac{15}{60}×1200\)
\(F_{t}=300N\)		 Comments Active
9 The SI unit 1 cubic metre per second is equal to  1000 litres per second 10 litres per second 1 litre per second 100 litres per second a 1 cubic metre per second (m³/s) = 1000 litres per second (L/s) Comments Active
10 The ratio of pressure intensity at a point and specific weight of the fluid at that point is called Kinetic head Pressure head Potential head Dynamic head b Pressure Head: The ratio of pressure intensity at a point and the specific weight of the fluid at that point is called pressure head
\(Pressure head=\frac{p}{ρg}\)
Hydraulic head/Piezo metric head: Hydraulic head or piezo metric head is a specific measurement of liquid pressure above a vertical datum. It is usually measured.
The sum of the pressure head and datum is known as piezo metric head. It is given by: \(\frac{p}{ρg}+z\)
The total energy of a flowing fluid can be represented in terms of head, which is given by -
\(\frac{p}{ρg}+\frac{V^{2}}{2g}+z\)
Where = pressure head, = velocity head and z = datum \(\frac{p}{ρg}\) \(\frac{V^{2}}{2g} \)		 Comments Active
11 In the Pitot tube, when kinetic energy is converted into pressure energy causing the liquid to rise in the vertical limb, the height of liquid is called______. Stagnation pressure head Dynamic pressure head Normal pressure head Static pressure head a Pitot tube: One of the most precise tools for measuring velocity is the Pitot tube.
• It operates on the concept that pressure increases at a point if the velocity of fluid becomes zero at that point because kinetic energy is converted into pressure at that point.
• It is made of a glass tube which is 90° bend and opens at both ends.
• It is placed in the pipe with its bend leg pointing upstream directly in front of the opening to form a stagnation point.
• The liquid rises in the vertical limb up to a height which is equal to stagnation pressure due to the conversion of kinetic energy into pressure energy.
• The Pitot tube is used to measure the stagnation pressure head only.
• For measuring both the stagnation pressure head and static pressure head, Pitot static tube is used.		 Comments Active
12 A cam and follower combination belong to the category of_____. lower pair rotating pair screw pair higher pair d A pair of toothed gearing, belt and rope drives, ball and roller bearings, and cam and follower are examples of higher pairs. Comments Active
13 For an incompressible fluid flowing through a pipe, the velocity of the fluid at different cross-sections will be proportional to: density of fluid () \(ρ\) area of cross-sections (A) 1/A 1/ \(ρ\) c The flow rate through the pipe = Velocity of flow Area of the pipe \(×\)
\(Q=V×A\)
For an incompressible fluid flowing through a pipe
\(V∝\frac{1}{A}, As Q is constant\)		 Comments Active
14 The specific volume of air is: 1.5 cubic metre per kilogram 1.25 cubic metre per kilogram 0.816 cubic metre per kilograms 1.125 cubic metre per kilogram c Specific volume of air 0.816 m3/kg and density is 1. 225 kg/m3 Comments Active
15 Which of the following statements is INCORRECT regarding assumption of Air standard cycle? Chemical composition of air does not change with temperature. Specific heat of working fluid varies with temperature. Heat loss to the surrounding is negligible. Specific heat of working fluid does not vary with temperature. b Assumptions during analysis:
1. The working fluid throughout the cycle is air and it is treated as an ideal gas 
2. The compression and expansion processes are taken as frictionless and adiabatic (no heat loss) i.e. they are reversible 
3. The chemical equilibrium of the working fluid is taken as constant  
4. The combustion process is replaced by well-defined heat addition processes the exhaust process is replaced by a heat rejection process that returns the air of the cycle to intake conditions
5. Since the gas is assumed as ideal the specific heats at constant volume and pressure are taken as constant.		 Comments Active
16 A motor is pumping 'Q' quantity of water through a pipe of diameter 100mm with a velocity of 5 m/s. After some years of working the pipe was required to be replaced with a new one whose diameter is 50mm. The velocity of water will be____. 25 m/sec 20 m/sec the same 2 m/sec b In this example, the volume flow rate remains the same before and afterward.
\(Therefore, Q_{1}=Q_{2}\)
\(∴A_{1}V_{1}=A_{2}V_{2}\)
Given data,
\(V_{1}=5 m/s, d_{1}=100mm, d_{2}=50mm\)
\(∴\frac{π}{4}×d12×V_{1}=\frac{π}{4}×d22×V_{2}\)
\(∴V_{2}=\frac{d12×V_{1}}{d22}\)
Substituting values of and V1, we get \(d_{1},d_{2}\)
\(V_{2}=20 m/s\)		 Comments Active
17 In a petrol engine. HC emission is found minimum in the exhaust during: Idling Acceleration Cruising Deceleration c At idling and deceleration: HC emissions tend to be higher due to rich mixtures and incomplete combustion.
During acceleration: HC emissions are typically high due to transient rich mixtures.
During cruising: The engine runs near ideal conditions, minimizing HC emissions.		 Comments Active
18 Which of the following is INCORRECT? Natural processes are irreversible processes. Irreversible processes can be shown on p-V diagram. Reversible processes are ideal processes. All spontaneous processes are irreversible processes. b Irreversible processes involve non-equilibrium states where pressure and volume are not uniquely defined at every instant, so they cannot be precisely represented as a continuous curve on a p-V diagram, unlike reversible processes. Comments Active
19 A reciprocating compressor has a bore diameter of 150 mm and a stroke of 200 mm. If volumetric efficiency of the compressor is 85%, then actual swept volume will be equal to: 3004 mm³ 3534.3 cm³ 3004 cm³ 3534.3 mm3 c Bore diameter (d) = 150 mm = 0.15 m
Stroke length (L) = 200 mm = 0.2 m
\(η_{vol}=0.85\)
Now the volume of compressor chamber \(V_{1}=\frac{π}{4}×d^{2}×L\)
\(V_{1}=0.003534 m^{3}\)
Therefore, swept volume V2 = V1 \(×η_{vol}\)
\(V_{2}=0.003534×0.85\)
\(=0.003004 m^{3}\)
\(V_{2}=3004cm^{3}\)		 Comments Active
20 The steam separator is installed______. close to the steam engine near the superheater far away from the steam engine near the economiser a The function of the steam separator is to remove entrained water particles. It is installed close to the steam engine or turbine. Comments Active
21 Brake power may be measured with the use of a/an: speedometer eddy current dynamometer bomb calorimeter Saybolt viscometers b A dynamometer is a device used for measuring the torque and brake power required to operate a driven machine. It has a device to measure the frictional resistance.
The following are the two types of dynamometers, used for measuring the brake power of an engine.
Absorption dynamometers: The entire energy or power produced by the dynamometer is absorbed by the friction resistance of the brake and is transformed into heat, during the process of measurement.
Example: Prony brake dynamometer, rope brake dynamometer, Hydraulic dynamometer, Eddy current dynamometer.
Transmission dynamometers: The energy is not wasted in friction but is used for doing work. The energy of power produced by the engine is transmitted through the dynamometer to some other machines where the power developed is suitably measured.
Example: Epicyclic – train dynamometer, Belt transmission dynamometer, Torsion dynamometer		 Comments Active
22 Choose the correct answer from the following four options?
S1: Higher volumetric efficiency due to more time for mixture intake in four stroke engine.
S2: Lower volumetric efficiency due to the lesser time for mixture intake in two stroke engine.		 S1 and S2 both are incorrect. S1 is correct and S2 is incorrect. S1 is incorrect and S2 is correct S1 and S2 both are correct d Volumetric efficiency: For internal combustion engines volumetric efficiency is defined as the ratio of the actual volume of mixture drawn into the cylinder during the intake period to the swept volume.
\(η_{v}=\frac{V_{m}}{V_{s}}\)
Where volumetric efficiency, = volume of mixture during intake period, swept volume. \(η_{v}=\) \(V_{m}\) \(V_{s}=\)
The volumetric efficiency is directly proportional to the actual volume of the mixture drawn during the intake period.
If the time of intake increases then more volume of the mixture is drawn into the cylinder which results in higher volumetric efficiency and vice – versa.
Also, with the increase in swept volume, volumetric efficiency decreases.		 Comments Active
23 In actual four-stroke petrol engine ignition takes places when the piston approaches. 35 before TDC \(°\) 35 after BDC \(°\) 35 after TDC \(°\) 35 before BDC \(°\) a 1st Stroke: With the inlet valve open, the piston first descends on the intake stroke, An ignitable mixture of gasoline vapour and air is drawn into the cylinder by the partial vacuum thus created.
2nd Stroke: The mixture is compressed as the piston ascends on the compression stroke with both valve closed.
3rd Stroke: As the end of the stroke approaches, the charge is ignited by an electric spark. The power stroke follows, with both valves still closed and the gas pressure, due to the expansion of the burned gas, pressing on the piston head or crown.
During this stroke, when the piston is 35áµ’ before TDC, ignition starts with a spark from the spark plug.
4th stroke: During the exhaust stroke the ascending piston forces the spent products of combution through the open exhaust valve. The cycle then repeats itself.		 Comments Active
24 In a thermosyphon cooling system, the water flows through the system: with the help of a turbine with the help of a compressor with the help of a pump automatically d Thermosyphon cooling system:
The phenomenon of thermosyphon is similar to the flow of air over the surface due to the density difference between hot and cooled air.
The thermosyphon phenomenon is, as the temperature of fluid increases its density decreases due to which the fluid starts moving upward and is replaced by the cooled fluid.
In this system, the circulation of water occurs naturally (automatically) due to the density difference between hot and cooled water.
The radiator is connected with a cylinder water jacket. The radiator is cooled by air flowing over it with the help of a fan or the motion of the vehicle.
The temperature of water in the cylinder water jacket increases due to which density decreases and water becomes lighter. The heated water then flows through the upper tank to the lower tank rejecting heat as it travels. The cooled water in the lower tank is then allowed to flow to the cylinder water jacket and the cycle repeats.
In this system, no pump is required for circulating water.
The limitation of this system is, the natural circulation of water takes place only after the engine is hot enough to cause the thermosyphon action.		 Comments Active
25 Double feed pump is commonly employed for medium size boilers small size boilers very large size boilers large size boilers a The double-acting pump has suction and discharge valves on both sides. So, there is continuous delivery of water to the boiler. The double-acting pump is generally used in medium size boilers. Comments Active
26 For the ice refrigeration system, which of the following statements holds true? The rate of refrigeration decreases with time The rate of refrigeration increases with time, The rate of refrigeration remains constant with time. Chilled liquid water is used as the refrigerant. a Ice refrigeration system: This is also an open-cycle or non-cyclic refrigeration system. In this method, ordinary ice is used for keeping the space at a temperature below the surrounding temperature. The temperature of ice is considered to be 0°C hence it can be used to maintain temperatures of about 5 to 10°C To use the ice for refrigerating effect a closed and insulated chamber is required On one side of the chamber, ice is kept while on the other side, there is a space which is to be cooled where some material to be cooled can be placed. Comments Active
27 Which of the following option is correct if reheating of steam or air in rankine cycle is performed during lower stages of turbine exhaust? Increases the dryness fraction No effect on dryness fraction First increases and then decreases the dryness fraction Decreases the dryness fraction a With reheating average temperature of heat addition increases. Hence, the efficiency of the cycle also increases. Further, the quality of steam is higher at the turbine exit since the turbine exit point moves rightward. Comments Active
28 Depending on______ the Hydraulic Gradient Line could rise or fall. changes in datum changes in velocity changes in diameter changes in pressure d Total energy line (T.E.L.): It is a line representing the sum of the pressure head, datum head, and velocity head.
\(TEL=Z+\frac{v^{2}}{2g}+\frac{P}{ρg}\)
Hydraulic Gradient Line (H.G.L.): It is a line representing the sum of the pressure head and datum head.
\(HGL=Z+\frac{P}{ρg}\)
Now, As we can see HGL depends on the pressure inside the pipe and the height of the pipe above the datum line.
It does not directly depend upon changes in the velocity or diameter of the pipe
As the datum or reference line is fixed, HGL can change if the elevation of the pipe changes or pressure inside the pipe changes.		 Comments Active
29 Sterling cycle consists of two reversible isothermal and two reversible adiabatic processes two reversible isothermal and two reversible isobaric processes two reversible adiabatic and two reversible isochoric processes two reversible isothermal and two reversible isochoric processes d Stirling cycle: A Stirling cycle consists of two reversible isothermal and two reversible constant volume (isochoric) processes. Comments Active
30 Water is flowing at the rate of 0.05 m³/s in a smooth pipe of diameter 500 mm and length of 900 m. What will be the nature of the flow? Take the kinematic viscosity of water as 0.02 stokes.  Turbulent flow Laminar flow Deal flow Transition flow a , Diameter d=500mm= 0.5m, kinematic viscosity = 0.02strokes=0.02 x 10-4 \(Q=0.05m^{3}/s \)
A x V =Q, \(V=\frac{Q}{A}=\frac{0.05}{\frac{π}{4}0.5×0.5}=0.2547m/sec\)
\(R_{e}=\frac{Vd}{ϑ}=\frac{0.2547×0.5}{2×10^{-6}}=63675 \)
, so flow is turbulent. \(R_{e}>4000\)		 Comments Active
31 The principle of single stroke reciprocating compressor is similar to: four-stroke IC engine vane type rotary compressor two-stroke IC engine semi hermitic compressor c Working of single-stage reciprocating compressor: It is similar to a diesel engine. However, as there is no combustion taking place, the cycle reduces to two strokes: suction and compression Comments Active
32 Clearance ratio of a reciprocating compressor is c= 0.03 If the ratio of suction to discharge volume is 8, then the volumetric efficiency of such compressor will be equal to___. 76% 64% 79% 37% c Given
C = 0.03
\(\frac{V_{1}}{V_{2}}=8\)
Then \(η_{v}=1+C-C(\frac{V_{1}}{V_{2}})=1+0.03-(0.03×8)\)
\(=0.79×100=79%\)		 Comments Active
33 Lubricating oil is insufficient in the case of mist lubricating system when throttle is 50% closed Fully closed Fully open Not depends on the throttle opening b Mist lubrication system:
In two – stroke engines, mist lubrication is used where crankcase lubrication is not suitable.
In a two – stroke engine, as the charge is compressed in the crankcase, it is not possible to have the lubricating oil in the sump. Hence, mist lubrication is adopted in practice. In such engines, the lubricating oil is mixed with the fuel, the usual ratio being 3% to 6%. The oil and fuel mixture is inducted through the carburettor.
During closed – throttle operation as in the case of the vehicle moving down the hill, the engine will suffer from insufficient lubrication as the supply of fuel is less. This is an important limitation of this system.		 Comments Active
34 In a boiler test 1250kg of coal is consumed in 24 hours. The mass of water evaporated is 13,000 kg and the mean effective pressure is 7 bar. The feed water temperature is 40°C, heating value of coal is 30000 kJ/kg. The enthalpy of 1 kg of steam at 7 bar is 2570.7 kJ. Equivalent evaporation per kg of coal is _____. 12.075 10.075 13.075 11.075 d Given
\(m_{w}=13000 Kg\)
\(m_{f}=1250 Kg\)
\(h=2570.7 KJ\)
Enthalpy of feed water (hw) = \(C_{P}×(T-0)\)
\(=(d) 184×40\)
\(=167.36KJ\)
Equivalent Evaporation \(me=\frac{m_{w}×(h-h_{w})}{m_{f}×2257}\)
\(me=\frac{13000×(2570.7-167.36)}{1250×2257}\)
Therefore me = 11.075		 Comments Active
35 If three forces are acting on the body as shown in the below figure and the body is in equilibrium, then the magnitude of forces F₁ and F₂ will be:
 F1 = 60 N and F2 = 50 N F1 = 50 N and F2 = 60 N F1 = 10 N and F2 = 10 N F1 = 50 N and Fâ‚‚ = 50 N d Here, we have a body on which three different planer forces are acting in different directions.
As per the law of equilibrium, the net algebraic sum of forces acting on the body shall be zero.
Now as per the sine rule for three vectors A, B and C in equilibrium condition,
\(\frac{A}{Sina}=\frac{B}{Sinb}=\frac{C}{Sinc}\)

Therefore, applying the sine rule here,
\(\frac{F_{1}}{sin120}=\frac{F_{2}}{sin120}=\frac{50}{sin120}\)
\(∴F_{1}=F_{2}=50N\)		 Comments Active
36 For power stroke of two-stroke petrol engine which of the below statements is correct? Two-stroke engine has valve arrangements First exhaust port uncovers then transfer Port uncovers Both transfer and exhaust port uncover simultaneously First transfer port uncovers then exhaust port uncovers b
In a two stroke engine, the downward power stroke begins after ignition. Near the end of this stroke, the piston uncovers the exhaust port, allowing the high – pressure exhaust gases to escape. Shortly after, the transfer (or scavenge) port is uncovered, allowing the next fuel/air mix to enter the cylinder, ready for the next cycle. This series of event is the basic principle of how a two – stroke engine operates.		 Comments Active
37 Which of the following is NOT a statement of the second law of thermodynamics? Principle of increase of entropy Clausius statement Principle of conservation of energy Kelvin-Planck statement c Kelvin-Planck statement: It is impossible to convert all the heat extracted from a hot body into work. In the heat engine, the working substance takes heat from the hot body, converts a part of it into work and gives the rest to the cold body. There is no engine that can convert all the heat taken from the source into work, without giving any heat into the sink. This means that for obtaining continuous work, a sink is necessary.Clausius statement: It is not at all possible to transfer heat from a cold body to a hot body without the expenditure of work by an external energy source.
Entropy: The second law of thermodynamics states that the total entropy of a system either increases or remains constant in any spontaneous process; it never decreases.		 Comments Active
38 For the given P-V diagram, which of the following statements holds true?
 Process 1-2 is an expansion process. Process 2-3 is an evaporation process. Process 4-1 is an expansion process Process 3-4 is a throttling process d Comments Active
39 The slope of the hydraulic gradient line is the slope of the energy gradient line if the pipe has a uniform cross section. not equal to greater than equal to less than c • The difference between E.G.L and H.G.L gives kinetic head.
• H.G.L lies below the E.G.L.
• For a uniform section pipe, the slope of H.G.L and E.G.L is equal because the velocity across the pipe is not changing, so the kinetic head remains constant.		 Comments Active
40 Select the correct statement linked with the Bernoulli's equation. The flow is assumed to be as 2-dimensional The liquid is ideal and compressible The velocity is non-uniform. The liquid is ideal and incompressible d \(\frac{P}{w}+\frac{v^{2}}{2g}+z=constant\)
The following are the assumptions made in the derivation of Bernoulli’s equation:
The fluid is ideal i.e. viscosity is zero.
The flow is steady.
The flow is incompressible.
The flow is irreversible.
The fluid is idea.		 Comments Active
41 Production of the conical surface by a gradual reduction in diameter along the length of the cylinder is known as: drilling operation knurling operation taper turning operation boring operation c Taper turning means to produce a conical surface by a gradual reduction in diameter from a cylindrical work piece.
Taper turning by attachment: This attachment is provided on a few modern lathes. Here the job is held parallel to the axis and the tool moves at an angle. The movement of the tool is guided by the attachment.
Advantages
• Both internal and external tapers can be produced.
• Threads on both internal and external taper portions can be cut.
• Power feed can be given
• A lengthy taper can be produced
• A good surface finish is obtained
• The alignment of the lathe centres is not disturbed
• It is most suitable for producing duplicate tapers because the change in the length of the job does not affect the taper		 Comments Active
42 Choose the correct answer from the following four options.
S1: In case of water cooled engine, installation must be at the front of vehicle.
S2: In case of air cooled engine, installation must be at the front of vehicle.		 S1 and S2 both are correct S1 is incorrect but S2 is correct S1 is correct but S2 is incorrect S1 and S2 both are incorrect b Air cooled engine:
The heat is taken by air which flow over the cylinder of engine.
In this system, fins are casted on the cylinder head and barrel which gives more conductive and radiating surface.
The design and installation is simpler due to absence of water jackets.
The air cooled engine is installed in the front of the vehicle.
The problem of freezing is not present in this type of system.
The weight per BHP of this system is low as compared to water cooled engine.
Water cooled engine:
The cooling agent in water cooled engine is water.
The wall temperature of water cooled engine is low as compared to air cooled engine due high thermal conductivity of water.
Generally, water cooled engine is not installed in front of vehicle.
To avoid the deposition of used water, recirculation system is required.
Due to corrosion inside the tube, fouling occurs in this type of cooling system.		 Comments Active
43 What is the reason for providing baffles in between water tubes in a Babcock and Wilcox boiler? To have better contact of flue gases with water tubes To regulate water flow To regulate steam flow To prevent buckling of water tubes a Baffle plates are provided to deflect hot flue gases. Baffle plates make sure that flue gases pass over the water tube properly. Comments Active
44 Chezy's formula is used for. Steady flow Internal flows Unsteady flow Open channel flows d \(m=\frac{Area of flow}{Wetted perimeter }→\frac{\frac{π}{4}d^{2}}{πd}=\frac{d}{4}\)
Chezy’s Equation: \(V=Cmi\)		 Comments Active
45 The first law of thermodynamics can be verified by. Joule's experiment Rankine's experiment Boyle's experiment Newton's law of cooling a The first law of thermodynamics can be verified by Joule's experiment. Work is done on the fluid kept in an insulated vessel by stirring of the paddle wheel. This work input to the fluid causes a rise in the temperature of the fluid Comments Active
46 A fusible plug is used to safeguard the boiler against excessive temperature safeguard the boiler against excessive pressure safeguard the boiler against excessive load stop feed water to the boiler a A fusible plug operates as a safety valve when dangerous temperatures, rather than dangerous pressures, are reached in a closed vessel. Fusible plugs are commonly installed in aircraft wheels, most typically in those of larger or high-performance aircraft. Comments Active
47 A roots blower compresses 0.08m air from I bar to 1.5 bar per revolution and ideal work input is found to be 3438.89Nm, then roots efficiency is 25.5% 68.6% 85.9% 45.8% c Given,
Vol. compressed per revolution (4V) = 0.08 m3
\(P_{1}=1 bar=10^{5}Pa\)
Roots blower efficiency = Actual work required /Ideal work required.
Actual work input per revolution = 4 V (P2-P1)
Therefore actual work input = 0.08 (0.5-1) 105 = 4000 N-m \(×\) \(×\)
Ideal work input = 3438.89 Nm.
Therefore \(η=\frac{3489.89}{4000}×100=85.9%\)		 Comments Active
48 In a two-stage reciprocating compressor, air inlet happens at 1.5 bar while the delivery pressure is 54 bar. The ideal intercooler pressure must be 11 bar 9 bar 12 bar 18 bar b \(P_{1}=1.5 bar, P_{2}=54 bar\)
So \(Pi=1.5×54\) \(∵P_{i}=P_{1}×P_{2}\)
\(P_{i}=9 bar\)
Hence the intermediate pressure will be 9 bar.		 Comments Active
49 From which of the following air standard cycles an Otto cycle may be obtained if constant pressure heat addition is removed? Brayton cycle Rankine cycle Diesel cycle Dual cycle d The dual Cycle, also called a mixed cycle or limited pressure cycle, is a compromise between otto and Diesel cycles.
Dual cycle is the thermodynamic cycle that combines the Otto cycle and the Diesel cycle. In this cycle, the heat addition occurs partly at constant volume and partly at constant pressure.

Different processes in the dual cycle are given below:
Different processes in the dual cycles are given below:
Process 1 – 2: Reversible adiabatic compression.
Process 2 – 3: Constant volume heat addition.
Process 3 – 4: Constant pressure heat addition.
Process 4 – 5: Reversible adiabatic expansion.
Process 5 – 1: Constant volume heat rejection.
If constant pressure heat addition is removed, it becomes an otto cycle.		 Comments Active
50 Venturimeter is used for measuring the flow rates of Incompressible flow Both Compressible and incompressible flows Flow having very low velocities Compressible flow a It is mainly used for incompressible fluids like liquids (water, oil) because the flow assumptions (constant density) hold true.
For compressible flows (like gases at high velocity or significant pressure changes), density changes significantly, complicating the measurement.
\(\frac{P}{w}+\frac{v^{2}}{2g}+z=constant\)		 Comments Active
51 Which of the following operation is used for grinding a flat surface? Form grinding Centerless grinding Cylindrical grinding Surface grinding d Form grinding: Used to produce complex profiles and shapes on workpieces. The grinding wheel is shaped to match the contour of the desired profile.
Centerless grinding: Used to grind the external surface of cylindrical workpieces without using centers to hold the workpiece. Common for mass production of shafts, pins, etc.
Cylindrical grinding: Used to grind external or internal cylindrical surfaces. The workpiece is held between centers or in a chuck.
Surface grinding: Specifically used for grinding flat surfaces to obtain a smooth finish or accurate dimensions. The workpiece is typically held on a magnetic chuck, and a rotating abrasive wheel moves over the surface.		 Comments Active
52 Which of the following is a non-positive displacement compressor? Rotary compressor Screw compressor Reciprocating compressor Centrifugal compressor d Centrifugal Compressors are not positive displacement compressors like the Reciprocating, Screw or Vane Compressors. They use very high speed spinning impellers (up to 60,000 rpm) to accelerate the air then diffuser to decelerate the air. Centrifugal compressor are rotodynamic type compressor. Comments Active
53 Which of the following refrigeration systems is used for cryogenic cooling? Vapour compression refrigeration system Liquid nitrogen refrigeration system Vapour absorption refrigeration system ice refrigeration system b Cryogenic cooling uses refrigerants, such as liquid nitrogen or solid carbon dioxide, directly. Cryogenic cooling systems leave the task of compressing and liquefying the coolant to the coolant supplier. One simply buys the coolant, uses it, and discards it into the atmosphere. Generally, from the user's perspective, the system is simpler, faster, and often better performing.
Cryogenic cooling can deliver extremely low temperatures should they be necessary. Liquid nitrogen can reach nearly -190°C By contrast, single-stage mechanical refrigeration has temperature limits of around -50°C		 Comments Active
54 Which of the following is an example of a reversible process? Frictionless relative motion. Heat transfer through an infinitesimal temperature difference. Isothermal expansion or compressible. Transfer of electricity through a resistor a Some example of a reversible process Comments Active
55 A perfect gas has bulk modulus at a constant temperature:  P \(ρ\) T \(ρ\) p/ \(ρ\) a Bulk modulus = K
= \(K=\frac{Change in pressure }{Volumetric strain}=\frac{dP}{-dV/V}\) \(-V\frac{dP}{dV}……(1) \)
For isothermal process: P.V=Constant……(2)
Differentiating equation (2)
PdV + VdP=0
PdV=-VdP
\( P=-V\frac{dP}{dV}……(3)\)
From (1) & (2)
K= \(-V\frac{dP}{dV}= -V(-\frac{P}{V})=P\)		 Comments Active
56 Which of the following thermodynamic properties is a result of the second law of thermodynamics? internal energy Temperature Enthalpy Entropy d Entropy is a result of the second law of thermodynamics.
Definition of entropy: The property of a system which measures the degree of disorder or randomness in the system is called entropy.		 Comments Active
57 Which of the following fluids has very low vapour pressure? Oil Air Mercury Water c The vapour pressure of mercury is 0.0017 mmHg at 25 °C which is one of the lowest among liquids. Comments Active
58 Which of the following is NOT a unit of evaporation rate? kg/hr kg/m³/hr kg/kg of fuel kg/m²/hr b Evaporation rate unit is given to be kg of steam/ hr, tonne / hr and kg of steam/kg of fuel. It is also defined by kg of steam per hour per unit heating surface. That is kg/m2/hr. Comments Active
59 Volumetric efficiency is the ratio of: clearance volume to the swept volume actual swept volume to the theoretical swept volume actual swept volume to the maximum theoretical volume swept volume to the maximum volume b η \(=\frac{actual swept volume}{Theoritical swept volume}\) Comments Active
60 Which of the following mechanical gauges can measure vacuum pressure by suitably modifying the graduations of the dial and adjusting the pointer? Bourdon tube pressure gauge Diaphragm pressure gauge Bellows pressure gauge Dead-weight pressure gauge a A Bourdon tube is a curved, hollow, elastic metal tube that tends to straighten when internal pressure increases.
When connected to a vacuum (i.e., pressure lower than atmospheric), the tube moves in the opposite direction — curling more tightly — and this motion can be calibrated to indicate vacuum pressure on the dial.
 Comments Active
61 The area under the p-V curve represents heat transfer in a flow process work transfer in a flow process heat transfer in a non-flow process work transfer in a non-flow process d The area below P-V diagram of a non-flow process represent work transfer

\(W=Pdv\)		 Comments Active
62 Head loss caused by an obstruction in the pipe having an area A and maximum area of obstruction as a is given by the expression: hobs = \((\frac{A}{C_{c}(A-a)}-2)^{2}×\frac{V^{2}}{2g}\) hobs = \((\frac{A}{C_{c}(A-a)}-1)^{3}×\frac{V^{2}}{2g}\) hobs = \((\frac{A}{C_{c}(A-a)}-1)^{2}×\frac{V^{2}}{g}\) hobs = \((\frac{A}{C_{c}(A-a)}-1)^{2}×\frac{V^{2}}{2g}\) d Minor Losses:
Loss due to sudden expansion: \(h_{L}_{(expansion)}=\frac{(V_{1}-V_{2})^{2}}{2g}\)
Where V₁ and V₂ are velocities before and after expansion.
Loss due to sudden contraction: \(h_{L}_{(contraction)}=(\frac{1}{C_{c}}-1)^{2}×\frac{V22}{2g}=\frac{0.5V22}{2g}\)
Where is the coefficient of contraction. \(C_{c}\)
Loss due to bend, pipe fitting: \(h_{L}_{(bend)}=\frac{Kv^{2}}{2g}\)
Where K is the bend coefficient.
Loss due to obstruction: Whenever there will be an obstruction in a pipe, loss of head will take place due to the reduction of the area of the cross-section of the pipe at the location where the obstruction is located. There will be sudden enlargement of the flow area beyond the obstruction and due to this reason, there will be a loss of head.
\(h_{L}_{(obstruction)}=(\frac{A}{C_{c}(A-a)}-1)^{2}×\frac{V^{2}}{2g}\)		 Comments Active
63 Which of the following materials are used as a cavitation resistant material to minimise the effect of cavitation? Cast iron Aluminium Copper Stainless steel d Methods to prevent cavitation: The pressure of fluid flowing through any hydraulic system should not be less than the vapour pressure.
• Special materials like stellite, bronze, nickel, stainless steel, are cavitation resistant material, it should be used.		 Comments Active
64 Which of the following gear trains will give smallest speed reduction from the first shaft to the last shaft Simple gear train Compound gear train Epicyclic gear trains Reverted gear train a The gear train which consists of only one gear on each shaft is known as simple gear train. Generally, it is used for small speed reduction. Comments Active
65 The condition under which W = is NOT true? \(pdV\) Effect due to gravity is neglected Process is irreversible No viscous effect within the system System is closed b Work done for irreversible process \(W=-12Vdp\) Comments Active
66 Continuity equation is based on which of the following applications? Conservation of Mass Conservation of Energy Conservation of Momentum Conservation of Energy and Momentum a The equation based on the principle of conservation of mass is called the continuity equation. Thus, for a fluid flowing through the pipe at all the cross-sections, the quantity of fluid flowing per second is constant.
\(ρ_{1}A_{1}V_{1}=ρ_{2}A_{2}V_{2}\)
Where, = density of the fluid, \(ρ\)
A = cross-section area of pipe at two different locations
V = velocity of the pipe at the measured cross-section		 Comments Active
67 A bar of 2 m² cross-sectional area is subjected to 150 N force, as shown in the given figure. What will be the stress developed in the bar?
 75 N/m² compressive 150 N/m² tensile 150 N/m² compressive 75 N/m² tensile d Stress= Force/Area=150/2=75 N/m² tensile Comments Active
68 The channel which carries water away from the power house after it has passed through the turbine in the hydroelectric plant, is called sump tail race head race forebay b • The tail race, containing tail water, is a channel that carries water away from a hydroelectric plant or water wheel.
• The water in this channel has already been used to rotate turbine blades or the water wheel itself. This water has served its purpose, and leaves the power generation unit or water wheel area		 Comments Active
69 Minor losses in head is caused due to. loss in pressure viscous action sudden enlargement friction c There are generally two types of losses
• Minor losses
• Major losses
Minor losses: Whenever there is a change in the cross-section, minor losses occur.
For e.g. sudden expansion, sudden contraction or bend in the pipes.
Major losses: Whenever the losses in the pipes are because of friction they are considered as major losses because there is a significant loss of energy because of friction.		 Comments Active
70 An economiser takes heat from____ for heating feed water. steam the furnace coal flue gases d Economizers are a type of heat exchanger used to recover heat from the flue gases of boilers (or other gaseous heat sources). The heat recovered is used to pre-heat the feed water, incoming combustion air or other streams Comments Active
71 Internal latent heat is defined as_____ heat required for complete conversion of saturated liquid to dry saturated vapour heat required for complete conversion of ice to water heat expended in overcoming the external resistance to change in volume heat expended in overcoming the internal molecular resistance to change in state from saturated water to dry steam d The internal latent heat is used to overcome the resistance of the molecular forces which oppose the change of state of the molecules brought about by the formation of steam. Comments Active
72 The ratio of area of flow to the wetted perimeter is called head loss hydraulic loss hydraulic radius radius of open channel c Hydraulic radius (A/P) is defined as the area of the flow section divided by the wetted perimeter, whereas, Hydraulic mean depth (A/T) is defined as the area of the flow section divided by the top water surface width. Comments Active
73 The major use of an economiser is_____. to heat up the incoming water by exhaust gases to heat up the incoming water with exhaust steam to heat up the incoming air by exhaust gases to heat up the pulverised fuel by exhaust a Economizer: It is also known as feed water heater. It is a device in which the waste heat of the flue gases is utilised for heating the feed water. Comments Active
74 Atmospheric pressure is taken as datum in: atmospheric pressure gauge pressure vacuum pressure absolute pressure b Gauge pressure:
It is defined as the pressure which is measured with the help of a pressure measuring instrument, in which the atmospheric pressure is taken as datum.		 Comments Active
75 For an incompressible flow, the volume flow rate of fluid with a given area of flow increases with____. increasing density increasing velocity decreasing density decreasing velocity b The continuity Equation is based on the principle of conservation of mass. For a fluid flowing through a pipe at all the cross-sections, the quantity of fluid per second is constant
The continuity equation is given as \(ρ_{1}A_{1}V_{1}=ρ_{2}A_{2}V_{2}\)
Density = C for an incompressible fluid. \(ρ\)
Continuity equation for an incompressible fluid A₁V₁ = A2V₂ = Q (Discharge of the flowing fluid)
From the above equation, it is clear that when the area of the flow is constant then discharge will increase with the increase in velocity.		 Comments Active
76 The frictional power of a single cylinder four-stroke engine is estimated to be 25 kW. If the mechanical efficiency is 75%, then the value of indicated power (in kW) will be: 75 150 125 100 d We know that the formula for mechanical efficiency is \(η_{m}=\frac{BP}{IP}[BP=Brake powe, IP=Indicated power\)]
So, \(0.8=\frac{BP}{IP}\)
s \(∴BP=0.8IP\)
Now,
We know that IP = BP + FP
So, IP = 0.8 IP + 25
Or,
0.2 IP = 25
\(∴IP=\frac{25}{0.2}=\frac{25}{(1/5)}=25×5\)
\(∴IP=125 kW\)		 Comments Active
77 A turbine develops 400 kW power under a head of 81 metres at 225 rpm. What will be the speed of the turbine under a head of 64 metres? 160 rpm 175 rpm 150 rpm 200 rpm d   \(P=400KW, H_{1}=81 m, N_{1}=225rpm, H_{2}=64m\)
\(\frac{N_{1}}{H_{1}}=\frac{N_{2}}{H_{2}}\)
\(\frac{225}{81}=\frac{N_{2}}{64}, N_{2}=200rpm\)		 Comments Active
78 The angle of repose is defined as the maximum inclination of plane at which a body remain in equilibrium over the inclined plane by the assistance of friction only. According to the definition of angle of repose the correct relation between angle of repose () and angle of friction () is: \(α\) \(∅\) < \(α \) \(∅\) \(α≠∅\) = \(α \) \(∅\) > \(α \) \(∅\) c The angle of repose or angle of sliding is defined as the minimum angle ofinclination of a plane with the horizontal such that a body placed on the plane just begins to slide down. \(α\)

Angle of friction: The angle of friction between any two sufaces in contact is defined as the angle which the resultant of the force of limiting friction and normal reaction N makes with the direction of normal reaction N. \(F_{lim}\)

Explanation:
\(tanθ=\frac{F_{lim}}{N}=μ\)
f = mg sin \(α\)
N = mg cos \( α\)
tan \(α=\frac{f}{N}\)
tan \(α=tanθ\)		 Comments Active
79 Which of the following is NOT a type of wet sump lubricating system? Splash type system: Light duty engine use this type of lubrication system. Oil is drawn by a pump delivered, extending the length of the crankcase by distrubuting pipe into splash troughs which are located under the big end of all the connecting rods. Pressure and splash type system: This system is used where the lubricating oil is pushed under pressure to the camshaft bearing.
* Also, oil is also supplied under pressure to pipes which direct the oil stream against the dippers on the big end of connecting rod bearing cap, and the splash lubricates the crankpin bearings.		 Pressure feed system: The pressure feed system is that in which oil is drawn in from the sump and forced to all the main bearings of the crankshaft through distribution channels.
* The pressure relief valve will also be fitted near the delivery point of the pump which opens when the pressure in the system attains a predetermined value.		 Pressure feed system b Types of lubricating systems:
Dry sump lubricating system
Wet sump lubricating system
Mist lubricating system
Wet sump lubricating system:
In this type, it contains oil in just the sump, serving as a reservoir and it uses a single oil pump. The oil circulating process seems to be fast in this lubricating system because the oil is pumped directly to the moving parts.
Working is fast, oil circulation is easier and less maintenance is required. However, oil circulation is limited as there is only one pump in this system.		 Comments Active
80 The size of a steam stop valve is designed by the size of the safety valve the pipe diameter it connects the amount of feed water the pipe length it connects b The steam stop valve is used to control the flow of steam from the boiler to the steam pipe.
Its size is generally selected based on the diameter of the pipe it connects to, so that it can handle the flow capacity without causing excessive pressure drop or flow restriction.
It must be large enough to pass the required steam flow through the pipe without causing bottlenecks.
Hence, the sizing depends on the pipe diameter, not on the safety valve size, feed water amount, or pipe length.		 Comments Active
81 For locomotive or portable boiler, which of the following pressure gauges is more suitable? Double tube bourdon gauge Diaphragm pressure gauge Single tube bourdon gauge Tubeless bourdon gauge a Considering the operational demands of locomotive and portable boilers, the double tube Bourdon gauge is the most suitable choice due to its enhanced rigidity and ability to withstand harsh conditions. Comments Active
82 The mathematical expression in terms of velocity (V) and acceleration due to gravity (g) for Kinetic Head is given by___. V2/2g V2/ 5g V2/g 2V2/g a Kinetic head (or velocity head) is a term used in fluid mechanics and hydraulic machines, derived from Bernoulli’s equation. It represents the height of a fluid column that corresponds to the kinetic energy per unit weight of the fluid.
\(Kinetic head or velocity head=\frac{V^{2}}{2g}\)		 Comments Active
83 Thermostat is used in a water cooled engine to maintain the: mass of the cooling water volume of the cooling water pressure of the cooling water temperature of the cooling water d Thermostat: When the engine is running, thermostat control the temperature of cooling water, which cools the engine.
The thermostat enables the engine to quickly attain desired temperature when it is cold and to keep it there after it has been reached.
Many water cooled engine (both four stroke and two stroke) have thermostat installed.
Two types of thermostats are used.
Bellows type
Wax type		 Comments Active
84 The value of nozzle efficiency doesn't depend on which of the following? Reynolds number of flow Material of nozzle Nusselt number of flow Angel of divergence of the divergent portion c Factors affecting nozzle efficiency:
Material of the nozzle
Shape and size of nozzle
Divergence angle
Nature of fluid and its state
Velocity of fluid
Friction
Turbulence in the flow path.		 Comments Active
85 Which of the following statement is FALSE about a hermetically sealed compressor? It is widely used for small capacity refrigeration system. It is more noisy because of rotating shaft. It require less space due to compactness Leakage of refrigerant is completely prevented b Hermetically sealed compressors are less noisy precisely because the motor and compressor are enclosed inside a sealed shell, reducing sound and vibration transmission. Comments Active
86 Determine the maximum possible reduction for cold rolling a 400 mm thick slab when coefficient of friction p = 0.07 and the roll diameter is 500 mm. 1.225mm 1.66 mm 1.44 mm 1.55 mm a Maximum Possible reduction in Rolling \((∆h)=μ^{2}R\)
Where the coefficient of friction, R is is the Roll radius. \(μ \)
Given = 0.07, R = 250 mm \(μ \)
\(∆h=μ^{2}R\)
\(∆h=(0.07)^{2}×250=1.225 mm\)		 Comments Active
87 Which of the following is INCORRECT? The entropy of isolated system increases in all real processes. The entropy of isolated system remains constant in reversible process The entropy of isolated system may decrease in irreversible process. The entropy of universe can never decrease c According to the second law of thermodynamics, the entropy of an isolated system increases with time It can never decrease.in irreversible process. Comments Active
88 Turgo turbine is a non-Palton wheel impulse turbine which is designed for___. medium head low head high head very high head a The Turgo turbine is an impulse turbine, and can handle flow rates that are higher than those a Pelton turbine can handle. This ability to deal better with large volumes of water gives the Turgo turbine an advantage when used in hydroelectric plants that have medium hydraulic heads. Comments Active
89 In actual 4S four-stroke diesel engine the injection of fuel inside the cylinder cut off when the piston approaches 25o before TDC 25o before BDC 25o after TDC 25o after BDC c The exact moment at which the inlet and outlet valve opens and closes with reference to the position of the piston and crank shown diagrammatically is known as valve timing diagram. It is expressed in terms of degree crank angle.

Event
Crank Angle (approximate)
Start of Injection (SOI)
10°–15° before TDC
End of Injection (EOI)
15°–25° after TDC
Start of Combustion
Just after TDC		 Comments Active
90 Which of the following is the correct application of ideal gas equation on T-S diagram of Rankine cycle? Valid everywhere Valid inside the vapor dome only Valid only on saturation curve None of the given options c Validity on Saturation Curve: The saturation curve is the line that separates the liquid and vapour regions on the T-S diagram. Along this curve, the substance is transitioning between phases, and it is considered to be in a saturated state. While not perfectly ideal, the ideal gas equation can be used as a reasonable approximation on the saturation curve, especially at high temperatures and low pressures.  Comments Active
91 Which of the following is NOT a type of steam trap? expansion type compression type bucket type float type b compression type is NOT a type of steam trap. Comments Active
92 For compression stroke of two-stroke diesel engine which of the below statements is correct? Both transfer and exhaust port close simultaneously Two-stroke engine has valve arrangements First transfer port closes then exhaust port closes First exhaust port closes then transfer Port closes c Two – stroke diesel engine: To produce power in a two – stroke engine the following operation takes place in the sequence given.
One working stroke for each revolution of the crankshaft is called two strokes, i.e. from TDC to BDC and then BDC to TDC.
A two – stroke engine does not required valve because in the two – stroke engine there are ports (transfer port and exhaust port) present in the engine cylinder which are covered and uncovered by piston reciprocation motion and charge transfer takes place.
Working of Two – stroke Engine: First Stroke (Suction and compression):
As the piston moves up from BDC towards TDC, it closes the inlet port, exhaust port, and transfer port.
Further upward movement of the piston results in compressing the mixture in the cylinder and opening of the inlet port.
The upward motion of the piston creates a partial vacuum inside the crankcase below the piston, and the air/fuel mixture is drawn into the crank – case through the inlet port.
The exhaust and transfer port remain closed during the operation of the upward stroke and the charge which reached above the piston during the previous stroke is compressed.
For the compression stroke of a two – stroke diesel engine, first transfer port closes then the exhaust port closes.		 Comments Active
93 A centrifugal pump is having manometric efficiency of 80% and a manometric head of 30 m. If the tangential velocity at the outlet of the pump is 20 m/s, then what will be the velocity of the whirl at the outlet of the pump? Take g = 10 m/s². 16.5 m/s 22 m/s 17.25 m/s 18.75 m/s d   \(η_{m}=80%, H_{m}=30m, g=\frac{10m}{sec^{2} }, u_{2}=20m/sec\)
Then, \(V_{w}_{2}=\frac{gH_{m}}{η_{m}u_{2}}=\frac{(10×30)}{(8×20)}=18.75m/sec.\)		 Comments Active
94 In a thermosyphon cooling system, the water flows through the system due to: entropy differences internal energy differences density differences volume differences c Thermosyphon cooling system: The phenomenon of thermosyphon is similar to the flow of air over the surface due to the density different between hot and cooled air.
The thermosyphon phenomenon is as the temperature of fluid increases its density decreases due to which the fluid starts moving upward and is replaced by the cooled fluid.
In this system, the circulation of water occurs naturally (automatically) due to the density difference between hot and cooled water.
The radiator is connected with a cylinder water jacket. The radiator is cooled by air flowing over it with the help of a fan or the motion of the vehicle.
The temperature of water in the cylinder water jacket increases due to which density decreases and water becomes lighter. The heated water then flows through the upper tank to the lower tank rejecting heat as it travels. The cooled water in the lower tank is then allowed to flow to the cylinder water jacket and the cycle repeats.
In this system, no pump is required for circulating water.
The limitation of this system is, the natural circulation of water takes place only after the engine is hot enough to cause the thermosyphon action.
 Comments Active
95 Which of the following is a dead weight governor? Hartnell Governor Proell Governor Pickering Governor Watt Governor b Porter governor is dead weight loaded type of gravity controlled centrifugal governor. Comments Active
96 Continuity equation is applicable to which of the following fluids?  Compressible and incompressible Compressible Incompressible Compressible and uniform flow a The continuity equation states that when fluid is in motion, then it should move in such a way that mass is conserved.

Rate of flow in section 1 – 1 = Rate of flow at section 2 – 2
\(ρ_{1}×A_{1}×V_{1}=ρ_{2}×A_{2}×V_{2}\)
This equation is applicable to compressible as well as incompressible fluid and is called a continuity equation.		 Comments Active
97 The ratio of the difference between maximum and minimum equilibrium speed to the mean equilibrium speed is:  Sensitiveness of Governor Isochronous Governor Hunting of Governor Stability of Governor a The sensitiveness is defined as the ratio of the difference between the maximum and minimum equilibrium speeds to the mean equilibrium speed. Comments Active
98 Which of the following basic component set is required for wet sump lubricating system? Oil Pump, strainer, pressure regulator, Oil filter, breather Oil Pump, strainer, Temperature regulator, Oil filter, breather Oil Compressor, strainer, Temperature regulator, Oil filter, breather Oil Compressor, strainer, pressure regulator, Oil filter, breather a Wet sump lubricating system:
The wet sump lubricating system consists of following components:
1. Oil pump
2. Strainer
3. Pressure regulator
4. Filter
5. Breather
* The figure of wet sump lubricating system is shown below:

Working principle:
The oil is distributed to the different engine parts with the help of oil pump. The oil is contained in oil sump which is located in the crankcase.
After lubricating engine parts, oil return to the sump by gravity. The pump gathers it up and pumps it through the engine lubrication system.
The fine mesh screen known as strainer is used to keep the unwanted particles out of the system that circulate oil.
There is a pressure relief valve that may be set to a certain value and automatically maintains the delivery pressure. When the oil pressure rises above the level for which the valve is designed, the valve opens, relieving the systems oil pressure by allowing some of the oil to return back to the sump.		 Comments Active
99 A cyclic heat engine operates between a source temperature of 727°C and a sink temperature of 27°C. Maximum efficiency of the engine is 70% 42.85% 30% 23.33% a For the maximum efficiency of the heat engine, the heat engine cycle should reject the least rate of heat which is only possible when it operates on the Carnot cycle. \((Q_{L})\)
For maximum efficiency of heat engines,
\(η=\frac{W}{Q_{H}}=\frac{T_{H}-T_{L}}{T_{H}}=1-\frac{T_{L}}{T_{H}}\)
Given \(T_{H}=727℃=1000 K, T_{L}=27℃=300K\)
\(η=1-\frac{T_{L}}{T_{H}}=1-\frac{300}{1000}\)		 Comments Active