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Past Questions — 2015
Prime costs do not include
A)
Indirect costs
B)
Administrative cost
C)
Direct costs
D)
Direct labour cost
Prime cost is the sum of direct costs only. It includes direct material, direct labour, and other direct expenses. Indirect costs are not part of prime cost; they belong to factory/overhead costs. Therefore, the correct answer is indirect costs. Options like direct costs and direct labour cost are included in prime cost, while administrative cost is also an indirect cost but the most direct and exact exclusion is indirect costs.
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. Which one is sitting opposite to Puia?
A)
Rina
B)
Muana
C)
Thanga
D)
Sanga
Let us place the six boys around a circle.
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 sit consecutively as Rina–Muana–Sanga or Sanga–Muana–Rina.
After arranging these conditions consistently, the person sitting opposite Puia comes out to be Rina.
So, the correct answer is Rina.
Work done in a free expansion process is
A)
Zero
B)
Minimum
C)
Maximum
D)
Always positve
In a free expansion, a gas expands into vacuum, so external pressure is zero. Work done is W = ∫ P_ext dV = 0 because P_ext = 0 throughout the process. Therefore, the work done is zero. It is not minimum or maximum, and it is not always positive.
Air vessel in a reciprocating pump are fitted to
A)
Increase delivery head
B)
Reduce suction head
C)
Smoothen delivery head
D)
Reduce acceleration head
An air vessel in a reciprocating pump is fitted to reduce the acceleration head and friction losses in the suction and delivery pipes by maintaining a more uniform flow. It helps in smoothing the discharge and reducing power required. Among the given options, the most correct purpose is to reduce acceleration head. The other options are incorrect because an air vessel does not increase delivery head or reduce suction head directly; smoothing delivery is a consequence, but the standard answer is reduction of acceleration head.
If the specific speed of a turbine is 800 the turbine should be
A)
Francis turbine
B)
Pelton turbine
C)
Kaplan turbine
D)
Fourneyron turbine
Specific speed indicates the type of turbine. Pelton turbines have low specific speed, Francis turbines have medium specific speed, and Kaplan turbines have high specific speed. A specific speed of about 800 falls in the high specific speed range, so the correct choice is Kaplan turbine. Fourneyron is an early form of reaction turbine and is not the standard classification used for this range.
The octane rating of petrol commercially available is usually
A)
90-100
B)
85-90
C)
75-80
D)
60-70
Commercial petrol generally has an octane rating in the range of about 85 to 90. Octane rating indicates the anti-knock quality of petrol; higher values mean better resistance to engine knocking. The other options are too low for regular commercial petrol: 75-80 and 60-70 are below usual petrol grades, while 90-100 is higher than what is usually available for standard commercial petrol.
In a thermal power plant thermodynamic cycle used is
A)
Otto
B)
Carnot
C)
Brayton
D)
Rankine
A thermal power plant (steam power plant) works on the Rankine cycle, which uses water/steam as the working fluid. In this cycle, water is pumped to high pressure, heated in the boiler, expanded in the turbine, and then condensed back to water. Otto and Brayton cycles are used in IC engines and gas turbine plants respectively, while Carnot is only an ideal theoretical cycle.
A single unit of 50 MW is not generally available with which type of power plant?
A)
Nuclear power plant
B)
Gas turbine power plant
C)
Steam power plant
D)
Diesel engine power plant
A 50 MW single generating unit is generally not associated with a diesel engine power plant because diesel plants are usually used for small capacities due to high fuel cost, size limitations, and maintenance issues. In contrast, nuclear, gas turbine, and steam power plants commonly have units of 50 MW or more.
Which of the following engines can work on very lean mixture?
A)
Petrol engine
B)
Diesel engine
C)
Wankel engine
D)
Two stroke engine
A diesel engine can work on a very lean mixture because it takes in only air during the suction stroke and fuel is injected directly into the hot compressed air. This allows combustion even when the overall air-fuel ratio is much higher than stoichiometric. Petrol engines generally need a near-stoichiometric mixture, while Wankel and two-stroke engines are not specifically known for operating on very lean mixtures.
A Kaplan turbine is a
A)
high head mixed flow turbine
B)
low head axial flow turbine
C)
impulse turbine, inward flow
D)
reaction turbine, outward flow
A Kaplan turbine is a reaction turbine designed for low head and high discharge conditions. Its runner has propeller-type blades and the flow passes through the turbine axially, so it is classified as a low head axial flow turbine. Option (a) is incorrect because Kaplan is not a high-head mixed-flow turbine; that description is closer to Francis-type behavior. Option (c) is wrong because impulse inward-flow turbines are Pelton-type concepts, not Kaplan. Option (d) is wrong because Kaplan is not an outward-flow turbine.
Which of the following is not a part of arc welding cost?
A)
Power consumption
B)
Cost of electrode
C)
Labor charges
D)
Soldering rods
In arc welding, the main cost components include power consumption, electrode cost, and labor charges. Soldering rods are used in soldering, not arc welding, so they are not part of arc welding cost.
Candid is to indirect as honest is to
A)
frank
B)
wicked
C)
untruthful
D)
truthful
‘Candid’ means frank or direct, so its opposite is ‘indirect’. Similarly, ‘honest’ means truthful, so its opposite is ‘untruthful’. Therefore the correct analogy is candid : indirect :: honest : untruthful.
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).
Standard AM radio broadcasts are confined to
A)
MF
B)
HF
C)
VHF
D)
UHF
Standard AM radio broadcasting uses the Medium Frequency (MF) band, typically around 530 kHz to 1700 kHz. HF is used for shortwave communication, while VHF and UHF are used for FM radio, TV, and other higher-frequency services. Therefore, the correct answer is MF.
If Vout is the induced voltage, a is a constant in volts/degrees, T & Tre f are the measured and reference temperature respectively, then the output equation for a thermocouple is given by
A)
Vout = a (T - Tre f)
B)
Vout = T (a - Tre f)
C)
Vout = a (T - Tyee)
D)
Vout = Pe Tre
For a thermocouple, the output voltage is proportional to the temperature difference between the measured junction temperature T and the reference junction temperature Tref. If a is the sensitivity constant in volts/degree, then the standard linear relation is Vout = a(T - Tref). Option (b) has the terms incorrectly arranged, option (c) is garbled/incorrect, and option (d) is unrelated.
Which of the following is not an ARM operating mode?
A)
User
B)
Supervisor
C)
Abort
D)
Define
ARM processor operating modes include User, Supervisor, Abort, IRQ, FIQ, Undefined, and System. Among the given options, User, Supervisor, and Abort are valid ARM modes. 'Define' is not an ARM operating mode, so it is the correct answer.