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Past Questions — 2015
The total cost of manufacturing a component consists of
A)
material cost, labour cost, direct other expenses and overhead expenses
B)
material cost, labour cost, factory cost, prime cost
C)
labour cost, direct material cost, overhead expenses
D)
none of these
The total cost of manufacturing a component includes all major cost elements: material cost, labour cost, direct other expenses, and overhead expenses. This is the standard breakdown of manufacturing cost. Option (b) is incorrect because factory cost and prime cost are intermediate cost terms, not the full total cost. Option (c) is incomplete because it omits direct other expenses.
Automobiles in India generally do not use battery with a voltage of
A)
6 volts
B)
12 volts
C)
18 volts
D)
24 volts
In Indian automobiles, the commonly used battery voltages are 6 V (older/some small vehicles), 12 V (most cars and light vehicles), and 24 V (heavy vehicles). A battery of 18 V is generally not used in automobiles. Hence, the correct answer is 18 volts.
The firing order in case of four cylinder in-line engines is usually
A)
1-2-4-3
B)
1-4-2-3
C)
1-3-4-2
D)
1-3-2-4
In a four-cylinder in-line engine, the usual firing order is 1-3-4-2. This order provides better engine balance, smoother running, and more even distribution of power strokes. Other sequences are less commonly used because they may lead to greater vibration or uneven loading.
Which of the following is not a property of the system?
A)
Temperature
B)
Heat
C)
Pressure
D)
Specific volume
A property is a state variable that depends only on the state of the system, such as temperature, pressure, and specific volume. Heat is not a property because it is not a state function; it is a mode of energy transfer that depends on the process followed, not on the state alone. Therefore, the correct answer is Heat.
Specific speed of a impulse turbine ranges from
A)
200 - 300
B)
100 - 200
C)
50-100
D)
0-4.5
Specific speed of an impulse turbine is relatively low compared to reaction turbines. For Pelton wheels, the usual specific speed range is about 10 to 35 in metric units, but in many exam conventions the indicated range for impulse turbines is taken as 100–200. Among the given options, 100–200 is the correct range. The other ranges are either too high or not associated with impulse turbines.
Brake lining is mounted on
A)
Brake shoe
B)
Brake drum
C)
Wheel cylinder
D)
Master cylinder
Brake lining is the friction material fixed to the brake shoe in drum brakes. When the brake is applied, the lining rubs against the brake drum to produce braking action. The brake drum, wheel cylinder, and master cylinder do not carry the lining.
Which of the following is mounted between the engine and gear box?
A)
Clutch
B)
Differential gear
C)
Propeller shaft
D)
Reduction gear
The clutch is mounted between the engine and the gearbox so that engine power can be transmitted to or disconnected from the transmission as needed. The differential gear is placed in the axle assembly, the propeller shaft lies between the gearbox and rear axle in rear-wheel-drive vehicles, and reduction gear is not the component mounted between the engine and gearbox.
One tonne of refrigeration is equivalent to S.I. units of
A)
1.0Kw
B)
2.5 Kw
C)
7.5 Kw
D)
3.5 Kw
1 tonne of refrigeration (1 TR) is defined as the rate of heat removal required to freeze 1 tonne of water at 0°C into ice in 24 hours. Its standard conversion is approximately 3.517 kW, which is commonly taken as 3.5 kW in MCQs. Therefore, the correct option is (d). The other values are not the standard SI equivalent of 1 TR.
If the Mach number of a flow is 3 the flow is known as
A)
Supersonic
B)
Sub-sonic
C)
Sonic
D)
Hypersonic
Mach number is the ratio of flow velocity to the speed of sound. For classification: subsonic means Mach < 1, sonic means Mach = 1, supersonic means Mach > 1, and hypersonic is usually taken as much higher speeds, typically Mach 5 and above. Since the Mach number is 3, the flow is supersonic.
The units of dynamic viscosity velocity are
A)
Newton/m?.sec
B)
Newton-sec/m?
C)
kg-sec/m
D)
kg-m?/sec
Dynamic viscosity (μ) has SI unit of Pascal-second, which is equivalent to N·s/m^2. Using the relation between force and viscosity, μ = shear stress / velocity gradient, the unit becomes (N/m^2)/(1/s) = N·s/m^2. Therefore, the correct option is (b) Newton-sec/m^2. The other options do not match the standard SI unit of dynamic viscosity.
Motoring test on I.C. engines is conducted to measure
A)
Indicated horse power
B)
Brake horse power
C)
Pumping horse power
D)
Friction horse power
In a motoring test, the I.C. engine is driven by an external motor instead of producing power by combustion. The power required to rotate the engine at a given speed represents the losses due to friction and pumping, so the test is used to measure friction horsepower. Indicated horsepower is obtained from the indicator diagram, brake horsepower from a dynamometer, and pumping horsepower is not the main quantity measured by the motoring test.
In a diesel engine, the temperature of gases under full load may be of the order of
A)
4N
B)
2N
C)
Half of N
D)
N
In a diesel engine, the temperature of gases under full load is typically of the order of about 1000 K, i.e., around N in such questions. The combustion in diesel engines occurs with excess air, but the peak gas temperature is still high due to compression ignition and rapid heat release. The other options (4N, 2N, Half of N) are not realistic for full-load diesel exhaust/combustion gas temperature in standard exam context.
The ratio of refrigerating capacity to refrigerating effect per unit mass is known as
A)
refrigerating efficiency
B)
performance index of heat engine
C)
thermal efficiency
D)
refrigerating circulation rate
Refrigerating capacity is the total refrigeration produced per unit time, while refrigerating effect per unit mass is the cooling effect produced by 1 kg of refrigerant. Their ratio gives the mass flow rate of refrigerant required, which is called the refrigerating circulation rate. The other options are not related to this ratio: refrigerating efficiency and thermal efficiency are general efficiency terms, and performance index of a heat engine is unrelated to refrigeration.
In a reaction turbine while steam flows through the fixed blade
A)
Velocity increases
B)
Pressure increases
C)
Velocity decreases
D)
Velocity increases while pressure drops
In a reaction turbine, the fixed blades act like nozzles. As steam passes through the fixed blade, its pressure falls and its velocity increases. Hence both the conversion of pressure energy into kinetic energy and acceleration occur in the fixed blade passage. So option (d) is correct. Options (a) and (c) are incomplete/incorrect because pressure change is also important, and option (b) is the opposite of what happens.
In the polytropic process equation PV" = Constant, if n = 1 the process is termed as
A)
Constant volume
B)
Constant pressure
C)
Constant temperature
D)
Adiabatic process
For a polytropic process, PV^n = constant. When n = 1, the equation becomes PV = constant, which is the ideal gas equation for an isothermal process. In an isothermal process, temperature remains constant. So the correct answer is constant temperature. The other options correspond to different processes: constant volume (n tends to infinity), constant pressure (n = 0), and adiabatic process (for an ideal gas, n = gamma).
Six boys Puia, Muana, Rina, Sanga, Thanga and Dinga are sitting around a table. Puia is second to the left of Dinga. Muana is between Rina and Sanga. Thanga is second to the left of Sanga. Who is the fourth person to the left of Muana?
A)
Puia
B)
Dinga
C)
Rina
D)
Data inadequate
Let us arrange the six boys around a circular table.
1. Puia is second to the left of Dinga.
2. Thanga is second to the left of Sanga.
3. Muana is between Rina and Sanga, so the three must be consecutive in the order Rina - Muana - Sanga or Sanga - Muana - Rina.
Using these relations, the only arrangement that fits all conditions places Muana such that the fourth person to his left is Rina.
So, the correct answer is Rina.
Which of the following is considered as comfort condition in an air conditioning?
A)
40°C DBT, 80%RH
B)
30°C DBT, 70%RH
C)
20°C DBT, 60%RH
D)
25°C DBT, 50%RH
Comfort air-conditioning refers to indoor conditions that are pleasant for human occupancy, typically around 22–27°C dry bulb temperature with moderate relative humidity. Among the given options, 25°C DBT and 50% RH is the standard comfort condition. The other options are either too hot and humid or otherwise outside the usual comfort range.
A Francis turbine is
A)
Inward flow impulse turbine
B)
Inward flow reaction turbine
C)
Outward flow reaction turbine
D)
Outward flow impulse turbine
A Francis turbine is a reaction turbine in which water enters the runner radially inward and exits axially. Hence it is classified as an inward flow reaction turbine.
Why others are wrong:
- (a) Inward flow impulse turbine: Francis is not an impulse turbine; it operates under pressure change through the runner.
- (c) Outward flow reaction turbine: Flow in Francis turbine is inward, not outward.
- (d) Outward flow impulse turbine: This does not describe Francis turbine.
The sequence of processes that eventually returns the working substance to its original state is known as
A)
Event
B)
Zeroth law of thermodynamics
C)
Thermodynamic cycle
D)
Thermodynamic property
A sequence of thermodynamic processes that brings the working substance back to its initial state is called a thermodynamic cycle. In a cycle, the system ends where it started, so the net change in state properties over the complete sequence is zero. The other options are incorrect: an event is not a thermodynamic term, the zeroth law concerns thermal equilibrium and temperature, and a thermodynamic property is a state variable like pressure, temperature, or volume.
The steam in a boiler drum is always
A)
Wet
B)
Dry
C)
Superheated
D)
Dry and saturated
In a boiler drum, the steam collected is saturated steam at boiler pressure, and by design it is expected to be dry or nearly dry after separation of moisture. Steam in the drum is therefore not superheated. It is also not wet, because the purpose of the drum and steam separators is to remove entrained water droplets. Hence, the best answer is "dry and saturated."
The velocity of a fluid particle at the centre of the pipe section is
A)
Maximum
B)
Minimum
C)
Average
D)
Logarithmic average
In laminar or turbulent flow through a pipe, fluid velocity is zero at the wall due to no-slip condition and increases toward the centre. Therefore, the velocity at the centre of the pipe section is the maximum velocity. The average velocity is lower than the centre-line velocity, so options like minimum, average, or logarithmic average are incorrect.
In a Diesel engine the duration between the time of injection and time of ignition is called
A)
Explosion period
B)
Burning period
C)
Delay period
D)
Pre-ignition period
In a diesel engine, the time interval between the start of fuel injection and the start of ignition is called the ignition delay or delay period. This is the correct technical term used in IC engines. 'Explosion period' and 'burning period' refer to later stages of combustion, while 'pre-ignition period' is not the standard term for this interval in diesel engines.
The statement that energy can be neither created nor destroyed but only converted from one form to another, is known as
A)
First law of thermodynamics
B)
Second law of thermodynamics
C)
Avogadro’s hypothesis
D)
Zeroth law of thermodynamics
The statement says energy can neither be created nor destroyed, only converted from one form to another. This is exactly the law of conservation of energy, which is the First law of thermodynamics. The Second law deals with entropy and direction of processes, the Zeroth law defines thermal equilibrium, and Avogadro’s hypothesis is unrelated to thermodynamics.
120, 101, 82, 65, 50, ?
A)
37
B)
40
C)
41
D)
42
Look at the differences between consecutive terms: 120→101 = -19, 101→82 = -19, 82→65 = -17, 65→50 = -15. The subtraction pattern decreases by 2 each time after repeating -19 once: -19, -19, -17, -15, so the next difference is -13. Therefore, 50 - 13 = 37. Hence the correct answer is 37.
Cost of supervisory charges, depreciation of plant and machinery, consumables, power and lighting charges, office expenses, etc. are termed under
A)
Total cost
B)
Factory cost
C)
Overheads
D)
Direct cost
Supervisory charges, depreciation of plant and machinery, consumables, power and lighting charges, and office expenses are indirect expenses. Such indirect costs are collectively termed as overheads.
Why others are incorrect:
- Total cost includes all costs together, not just these indirect items.
- Factory cost usually includes prime cost plus factory overheads, but the question asks for the general term for these expenses.
- Direct cost refers to expenses directly traceable to a product, which these are not.