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Past Questions — 2016
Which one is not the part of gas turbine?
A)
Compressor
B)
Regenerator
C)
Combustion Chamber
D)
Piston
A gas turbine consists of a compressor, combustion chamber, turbine, and sometimes a regenerator/heat exchanger. A piston is a component of a reciprocating internal combustion engine, not a gas turbine. Therefore, the correct answer is Piston.
A prime mover in which gradual changes in the momentum of a fluid are utilised to produce rotation of the mobile member is
A)
Electric Motor
B)
Turbine
C)
Diesel Engine
D)
None of these
A turbine is a prime mover that converts the gradual change in momentum of a flowing fluid into rotational motion of its rotor (mobile member). In turbines, the fluid acts on blades and transfers energy continuously. An electric motor uses electrical energy, and a diesel engine works on combustion pressure, not fluid momentum change. Hence, the correct answer is turbine.
Petrol engine works on
A)
Diesel cycle
B)
Dual cycle
C)
Otto cycle
D)
None of these
A petrol engine is a spark-ignition engine, and its ideal thermodynamic cycle is the Otto cycle. Diesel engines work on the Diesel cycle, while the Dual cycle is a combination of Otto and Diesel characteristics and is not the standard cycle for petrol engines. Therefore, the correct answer is Otto cycle.
The octane rating of petrol commercially available is usually
A)
85-90
B)
90-100
C)
100-110
D)
110 - 125
The octane number of commercially available petrol is usually in the range of about 85 to 90. This reflects its anti-knock quality for spark-ignition engines. Options (b), (c), and (d) are too high for ordinary commercial petrol; such values correspond to premium or highly specialized fuels, not the usual retail petrol grade.
Which one is not the method of cooling an I.C. engine?
A)
Air cooling
B)
Oil cooling
C)
Water cooling
D)
Steam cooling
I.C. engines are commonly cooled by air cooling, water cooling, and sometimes oil cooling. Steam cooling is not used as a standard method of cooling in I.C. engines. Therefore, the correct answer is Steam cooling.
The principle of a radiator of an engine cooling system is to
A)
Act as a reservoir for the water
B)
Cause heat flow by convection currents
C)
Spread out the hot water over a large area
D)
Increase the air speed as it flows over the hot surface
A radiator removes heat from the engine coolant by exposing the hot water/coolant to a large surface area so that heat can be transferred to the surrounding air. This is the basic principle of a radiator. Option (a) describes a header tank/reservoir, not the main cooling principle. Option (b) is incomplete because convection helps, but the radiator’s key principle is increasing heat transfer area. Option (d) refers to the effect of a fan or air flow, not the radiator itself.
In a four-stroke engine, each cylinder has
A)
One valve
B)
Two valves
C)
Three valves
D)
Four valves
In a basic four-stroke engine, each cylinder generally has two valves: one inlet valve and one exhaust valve. The inlet valve admits the air-fuel mixture (or air in diesel engines), and the exhaust valve removes the burnt gases. Hence, the correct answer is Two valves. The other options are not the standard basic configuration.
An engine has a clearance volume of 100cm³ and swept volume of 800cm³. The compression ratio is
A)
7:1
B)
9:1
C)
10:1
D)
8:1
Compression ratio = (Swept volume + Clearance volume) / Clearance volume. Here, = (800 + 100) / 100 = 900 / 100 = 9:1. So the correct calculated value is 9:1, which corresponds to option (b).
Mark the one alternative that is nearest in meaning to the word - Nullify
A)
Impress
B)
No effect
C)
Seclude
D)
Astound
“Nullify” means to make something invalid, cancel it out, or have no effect. Among the given options, “No effect” is the nearest in meaning. The other options are unrelated: “Impress” means influence favorably, “Seclude” means isolate, and “Astound” means surprise greatly.
The resultant upward thrust experienced by a body when immersed in the fluid is known as
A)
Equilibrium of floating bodies
B)
Buoyancy
C)
Weight ofa body
D)
None of these
The upward force exerted by a fluid on a body immersed in it is called buoyancy or buoyant force. This is the resultant upward thrust mentioned in the question. Option (a) is a condition related to floating bodies, (c) is unrelated, and (d) is incorrect because the correct term is given in (b).
Which one is not components of cost?
A)
Prime cost
B)
Factory cost & Office cost
C)
Total cost
D)
None of these
In cost accounting, the main components of cost are prime cost, factory/works cost, office cost, and total cost. Since all options (a), (b), and (c) are components of cost, the correct choice for 'which one is not components of cost' is 'None of these'.
Indirect Expenses is known as overhead charges, on-cost, burden or indirect charges. Which one is not included in classification of Indirect Expenses?
A)
Factory expenses
B)
Administration & Selling expenses
C)
Distribution expenses
D)
None of these
Indirect expenses (overheads) are commonly classified into factory/workshop expenses, administration expenses, selling expenses, and distribution expenses. Since all the options in (a), (b), and (c) are valid classes of indirect expenses, none of them is excluded. Therefore, the correct answer is (d) None of these.
A process, which can be reversed, cannot lead to the initial state of the system and the surroundings without external inputs, is
A)
Irreversible process
B)
Reversible process
C)
Constant process
D)
None of these
A reversible process is one that can be reversed at any stage, and both the system and surroundings can be restored to their initial states with no net change. The question states a process that cannot return the system and surroundings to the initial state without external input, which is the definition of an irreversible process. Hence, option (a) is correct. Option (b) is wrong because reversible processes are fully reversible. Option (c) is not a thermodynamic term here, and (d) is incorrect because (a) fits the statement.
The amount (percentage) of water in the air is known as
A)
Density
B)
Specific gravity
C)
Humidity
D)
None of these
The amount of water vapour present in air is called humidity. In refrigeration and air-conditioning, humidity refers to the moisture content of air. Density and specific gravity are unrelated to moisture content, so they are incorrect.
“The law of conservation of energy, according to which the total energy of an isolated system in all its forms remains constant. For a closed system executing a cycle only through heat and work, the change in internal energy is zero”, known as
A)
Second Law of Thermodynamics
B)
Newton’s First Law of Motion
C)
First Law of Thermodynamics
D)
None of these
The statement describes conservation of energy and says that for a closed system undergoing a cycle, the change in internal energy is zero. This is exactly the First Law of Thermodynamics. The Second Law deals with direction of heat flow and entropy, while Newton’s First Law is about inertia, not thermodynamic energy conservation.
As applied to steering, the abbreviation P.A.S. stands for
A)
Pump assisted system
B)
Pump aided steering
C)
Power activated system
D)
Power assisted steering
In automobile engineering, P.A.S. in the context of steering means Power Assisted Steering, which is a steering system that reduces driver effort by using hydraulic or electric assistance. The other options are not the standard expansion of P.A.S.
Cetane number of Diesel oil normally available in market is in the range
A)
45-50
B)
60-65
C)
75 - 80
D)
90-100
Cetane number indicates the ignition quality of diesel fuel. Commercial diesel normally available in the market has a cetane number in the range of about 45 to 50. Higher values mean better ignition quality, but extremely high values like 75–100 are not typical for ordinary diesel fuel.
Which one is not included in one of advantages of gas turbine?
A)
Braking is not effective due to very high speed
B)
Gas turbine is smooth in operation and continuous in performance
C)
It does not have reciprocating parts, hence it is easy to balance. It is free from vibration.
D)
None of these
Gas turbines are known for smooth, continuous operation, absence of reciprocating parts, easy balancing, and very low vibration. These are real advantages, matching options (b) and (c). Option (a) is not an advantage of gas turbines; in fact, ineffective braking due to high speed is a limitation, not a benefit. Therefore, the correct answer is (a).
A substitute for “one who likes to spend time with others” in one word can be
A)
Introvert
B)
Commoner
C)
Extrovert
D)
Extraordinary
An extrovert is a person who is outgoing and enjoys being with other people, so it matches "one who likes to spend time with others." Introvert means a shy person who prefers solitude. Commoner means an ordinary person, and extraordinary means exceptional or unusual, so neither fits.
Refrigerant usually used in refrigeration in aeroplane
A)
CO₂
B)
Air
C)
Freon
D)
None of these
In aircraft refrigeration systems, air is usually used as the refrigerant because it is light, safe, readily available, and suitable for the air cycle refrigeration used in aeroplanes. CO₂ and Freon are not the usual refrigerants for aircraft cabin cooling. Therefore, the correct answer is Air.
A closed vessel made of high quality steel in which stream is generated from water by the application of heat, is known as
A)
Steam nozzle
B)
Steam Generator (or) a boiler
C)
Steam Jet Draught
D)
None of these
A closed vessel made of high-quality steel in which steam is generated from water by the application of heat is called a boiler, also known as a steam generator.
- Option (a) Steam nozzle: used to convert pressure energy of steam into kinetic energy, not to generate steam.
- Option (c) Steam Jet Draught: a draught-producing device in boilers, not the boiler itself.
- Option (d) None of these: incorrect because the definition matches a boiler.
The next number in the following sequence would be 3, 5, 8, 13, 21, 34, ?
A)
22
B)
55
C)
53
D)
47
This is a Fibonacci-type sequence, where each term is the sum of the two preceding terms: 3, 5, 8, 13, 21, 34. So the next term is 21 + 34 = 55. The other options do not satisfy this pattern.
At the first sight a petrol engine is identified by
A)
Cylinder size
B)
Power output
C)
Operating speed
D)
Spark plug
A petrol (spark-ignition) engine is identified at first sight by the presence of a spark plug in the cylinder head, which is used to ignite the air-fuel mixture. Diesel engines do not use spark plugs; they use compression ignition. Cylinder size, power output, and operating speed are not distinctive visual identifiers of a petrol engine.
A rotodynamic pump, which does not generate centrifugal force for building up pressure, but pressure is generated by flow of liquids over the blades of aerofoil section just like the lifting action of the wings of an aeroplane, is known as
A)
Axial flow pump
B)
Centrifugal pump
C)
Vertical Turbine pump
D)
None of these
An axial flow pump is a rotodynamic pump in which the pressure rise is mainly due to the lift produced by the aerofoil-shaped blades, similar to the wings of an aeroplane. The liquid flows essentially parallel to the pump shaft, and centrifugal action is not the primary mechanism for pressure generation. A centrifugal pump, by contrast, develops pressure mainly due to centrifugal force. Hence, the correct answer is Axial flow pump.
For calculating head lost due to water flow in the pipe, the general formula (Darcy & Weisbacks formulae) used is
A)
h=4flv²/2gd
B)
h=14flv²/2gd
C)
h=flv²/2gd
D)
None of these
The Darcy-Weisbach formula for head loss due to friction in a pipe is commonly written as h_f = 4fLv² / (2gD) when f denotes the coefficient of friction in the Fanning form used in many exam texts. Here, L is pipe length, v is mean velocity, g is acceleration due to gravity, and d (or D) is pipe diameter. Option (a) matches this standard form. Option (c) omits the factor 4, and option (b) is not a correct formula.