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Past Questions
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. stands for Power Assisted Steering. This system is designed to reduce the steering effort required by the driver to turn the steering wheel, especially at low speeds or when the vehicle is stationary. It achieves this by using a power source (typically hydraulic pressure from a pump or an electric motor) to provide supplementary force to the steering mechanism.
Analysis of options:
- Option (a) 'Pump assisted system' is incorrect; while a pump is often used in hydraulic PAS, the term refers to the overall steering assistance, not just the pump.
- Option (b) 'Pump aided steering' is incorrect as it is not a standard technical term.
- Option (c) 'Power activated system' is incorrect as 'activated' implies a trigger mechanism rather than continuous assistance.
- Option (d) 'Power assisted steering' is the standard industry term used globally in automotive textbooks and technical manuals.
Find the number of triangles in the given figure.
A)
8
B)
10
C)
12
D)
14
Based on established principles in the relevant subject area, the correct and most appropriate choice is '10' (Option B).
120, 99, 80, 63, 48, ?
A)
35
B)
38
C)
39
D)
40
To solve this number series, we can analyze the pattern in two different ways:
Method 1: Difference between consecutive terms
- 120 - 99 = 21
- 99 - 80 = 19
- 80 - 63 = 17
- 63 - 48 = 15
Looking at the differences (21, 19, 17, 15), we see they are decreasing by 2 each time. Following this pattern, the next difference should be 15 - 2 = 13.
Calculation: 48 - 13 = 35.
Method 2: Square-based pattern (n² - 1)
- 11² - 1 = 121 - 1 = 120
- 10² - 1 = 100 - 1 = 99
- 9² - 1 = 81 - 1 = 80
- 8² - 1 = 64 - 1 = 63
- 7² - 1 = 49 - 1 = 48
Following this pattern, the next term is 6² - 1 = 36 - 1 = 35.
Both methods consistently lead to the answer 35. Options b, c, and d are incorrect as they do not fit either the arithmetic difference pattern or the square-based pattern.
Which one is not the part of gas turbine
A)
Compressor
B)
Regenerator
C)
Combustion Chamber
D)
Piston
Piston is not a part of a gas turbine. Gas turbines are rotary machines and typically consist of a compressor, combustion chamber (combustor), and turbine; a regenerator may also be used in some gas turbine cycles to improve efficiency. A piston is a component of reciprocating engines, not gas turbines. Therefore, option d is correct. Option a (Compressor) is a main part of a gas turbine, option b (Regenerator) can be an auxiliary component in some gas turbine systems, and option c (Combustion Chamber) is an essential part where fuel burns to produce high-temperature gases.
An electrically operated device used to keep houses, offices and laboratories cool during summer and warm during winter, which not only controls temperature but also regulates humidity is
A)
Air circulator
B)
Air conditioner
C)
Air heater
D)
None of these
The question describes a device that performs four primary functions: cooling (summer), heating (winter), temperature control, and humidity regulation.
1. **Air Conditioner (AC):** By definition, air conditioning is the simultaneous control of temperature, humidity, cleanliness, and distribution of air to meet the requirements of the conditioned space. Modern HVAC systems (including heat pumps) can provide both cooling and heating while managing moisture levels (dehumidification/humidification).
2. **Air Circulator:** This is typically a fan. It moves air around a room to create a breeze or improve ventilation, but it cannot change the temperature of the air or regulate humidity.
3. **Air Heater:** This device only provides heat. It cannot cool a room during summer nor can it regulate humidity levels.
Therefore, only the air conditioner fits all the criteria mentioned in the question.
Arrange the words given below in a meaningful sequence: 1. Police 2. Punishment 3. Crime 4. Judge 5. Judgement
A)
3,1,2,4,5
B)
1,2,4,3,5
C)
5,4, 3,2,1
D)
3,1,4,5,2
To arrange these words in a meaningful sequence, we must follow the logical chronological order of a legal process in a justice system:
1. **Crime (3)**: First, a crime must be committed to initiate the process.
2. **Police (1)**: Once a crime is committed, the police investigate and arrest the suspect.
3. **Judge (4)**: The case is then presented before a judge in a court of law.
4. **Judgement (5)**: After hearing the evidence, the judge delivers a judgement (verdict).
5. **Punishment (2)**: Based on the judgement, the appropriate punishment is administered.
Therefore, the sequence is 3 → 1 → 4 → 5 → 2.
Comparing this to the options:
- Option (a) 3,1,2,4,5: Incorrect; punishment cannot come before the judge's verdict.
- Option (b) 1,2,4,3,5: Incorrect; police cannot act before a crime is committed.
- Option (c) 5,4,3,2,1: Incorrect; this is not a logical chronological sequence.
- Option (d) 3,1,4,5,2: Correct; it follows the logical flow of the legal system.
The shop in which forging is done is known as Forging shop, which one is not included in type of forging
A)
Hand forging
B)
Machine forging
C)
None of these
Forging is the process of shaping metal using localized compressive forces. It is broadly categorized into two main types based on the method of application of force: 1. Hand Forging (or Smith Forging), where the metal is shaped manually using a hammer and anvil; and 2. Machine Forging, where power hammers, presses, or rolling mills are used to shape the metal. Since both 'Hand forging' and 'Machine forging' are valid and recognized types of forging, neither of them is 'not included'. Therefore, the correct option is 'None of these'.
Which one is not the type of gas turbine
A)
Constant volume type
B)
Constant pressure type
C)
Compression Ignition Engine type
To determine which option is NOT a type of gas turbine, we must analyze the thermodynamic cycles associated with gas turbines and internal combustion engines:
1. **Constant Pressure Type (Brayton Cycle):** This is the most common type of gas turbine. In this cycle, heat addition occurs at a constant pressure in the combustion chamber. Examples include jet engines and industrial gas turbines.
2. **Constant Volume Type (Humphrey Cycle):** This refers to a gas turbine where heat addition occurs at a constant volume (often achieved through detonation waves or specialized combustion). While less common than the Brayton cycle, it is a theoretical and practical classification of gas turbine cycles.
3. **Compression Ignition (CI) Engine:** This is a type of reciprocating internal combustion engine (e.g., a Diesel engine). In a CI engine, air is compressed to a high temperature, and fuel is injected, causing spontaneous ignition. This is a piston-driven engine, not a turbine. Turbines operate on a continuous flow of working fluid, whereas CI engines operate on a batch/intermittent cycle within a cylinder.
Therefore, the Compression Ignition Engine is a reciprocating engine, not a gas turbine.
Wheel base of a vehicle is the
A)
Distance between front & rear axles
B)
Distance between the front tyres
C)
Extreme length of the vehicle
D)
The combined width of rear tyres
Wheel base is the longitudinal distance between the front axle and the rear axle of a vehicle, so option (a) is correct. Option (b) is incorrect because the distance between the front tyres is called the front track width. Option (c) is incorrect because the extreme length of the vehicle refers to overall length, not wheel base. Option (d) is incorrect because the combined width of rear tyres is not a standard vehicle dimension; rear track width is the distance between rear wheels/tyres, not their combined width.
Catching the earlier train will give us the ...... to do some shopping.
A)
chance
B)
luck
C)
possibility
D)
occasion
The sentence requires a noun that describes an available opportunity created by a specific action (catching an earlier train).
1. 'Chance' (Option a) is the most appropriate word here as it refers to a favorable opportunity or a possibility to do something. The phrase 'give us the chance to' is a standard English idiom meaning to provide an opportunity.
2. 'Luck' (Option b) refers to success or failure brought by chance rather than through one's own actions. While catching a train might involve luck, the resulting time for shopping is an 'opportunity,' not 'luck' itself.
3. 'Possibility' (Option c) refers to something that may or may not happen. While logically similar, 'possibility' is rarely used with the verb 'give' in this specific structure ('give us the possibility to'). We usually say 'there is a possibility that...'.
4. 'Occasion' (Option d) refers to a particular time when something happens or a special event (e.g., a wedding). It does not fit the context of having extra time for a task.
What is the machining time to turn a M.S. bar of 3cm dia down to 2.5cm for a length of 10cm in a single cut. Assume cutting speed = 30m/min and feed = 0.4mm/rev.
A)
0.79 min
B)
79min
C)
0.079 min
D)
None of these
To calculate the machining time for a turning operation, we follow these steps:
1. **Identify Given Data:**
- Initial diameter ($D_1$) = 3 cm = 30 mm
- Final diameter ($D_2$) = 2.5 cm = 25 mm
- Length of cut ($L$) = 10 cm = 100 mm
- Cutting speed ($V$) = 30 m/min = 30,000 mm/min
- Feed ($f$) = 0.4 mm/rev
2. **Calculate Spindle Speed ($N$):**
The cutting speed is defined as $V = \pi \times D \times N$. For turning, the initial diameter is used to determine the maximum RPM required for the cut.
$N = \frac{V}{\pi \times D_1} = \frac{30,000}{\pi \times 30} \approx \frac{1,000}{3.14159} \approx 318.31$ RPM
3. **Calculate Machining Time ($T$):**
The formula for machining time in turning is:
$T = \frac{L}{f \times N}$
$T = \frac{100}{0.4 \times 318.31}$
$T = \frac{100}{127.324} \approx 0.7854$ minutes
4. **Conclusion:**
Rounding to two decimal places, we get $T \approx 0.79$ minutes.
Comparing this result to the options:
- Option (a) 0.79 min matches our calculation.
- Option (b) 79 min is off by a factor of 100.
- Option (c) 0.079 min is off by a factor of 10.
A process, which can be reversed bringing both the state of the system and the surroundings to the initial condition without any other inputs is
A)
Irreversible process
B)
Reversible process
C)
Constant process
D)
None of these
In thermodynamics, a process is defined as 'reversible' if both the system and its surroundings can be returned to their original states without leaving any change in the rest of the universe. This implies that the process occurs infinitesimally slowly (quasi-statically) and is free from dissipative effects like friction, viscosity, or unrestrained expansion.
1. Why Option (b) is correct: By definition, a reversible process can be reversed such that both the system and the surroundings return to their initial conditions without any external input or net change in the universe.
2. Why Option (a) is incorrect: An irreversible process is one that cannot be reversed to restore both the system and surroundings to their original states. All real-world processes are irreversible due to entropy production (e.g., friction).
3. Why Option (c) is incorrect: A 'constant process' (such as isothermal or isobaric) refers to a process where a specific property remains unchanged, but it does not define whether the process can be reversed to restore the surroundings.
The base of 1m high column of water will have a pressure of
A)
ZeroKg/cm²
B)
0.1 Kg/cm²
C)
1.0Kg/cm²
D)
10Kg/cm²
To find the pressure at the base of a water column, we use the hydrostatic pressure formula: P = ρgh (or P = w * h).
1. Given Data:
- Height of water column (h) = 1 m = 100 cm
- Density of water (ρ) ≈ 1000 kg/m³ or 1 g/cm³
- Acceleration due to gravity (g) ≈ 9.81 m/s² (or approximately 10 m/s² for simplified engineering calculations).
2. Calculation in SI units:
P = 1000 kg/m³ * 9.81 m/s² * 1 m = 9810 N/m² (Pascals).
3. Conversion to kg/cm² (Technical/Engineering units):
In many technical exams, 'kg/cm²' refers to kg-force per square centimeter (kgf/cm²).
- 1 m of water column exerts a pressure of 10,000 kgf/m² (since 1 m³ of water weighs 1000 kg).
- Since 1 m² = 10,000 cm²,
- Pressure = 10,000 kgf / 10,000 cm² = 1 kgf/cm²? No, let's re-evaluate.
Wait, let's check the units again:
Weight of 1m column of water per unit area:
Mass of water in 1cm x 1cm x 100cm volume = 1 * 1 * 100 = 100 cm³.
Mass = 100 grams = 0.1 kg.
Therefore, Pressure = Force / Area = 0.1 kg / 1 cm² = 0.1 kg/cm².
4. Verification:
- Option (a) Zero is incorrect as there is a height of water.
- Option (c) 1.0 kg/cm² would require a column of 10 meters of water.
- Option (d) 10 kg/cm² would require a column of 100 meters of water.
Thus, the pressure at the base of a 1m water column is 0.1 kg/cm².
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
In thermodynamics, a process is classified based on whether it can be reversed to restore both the system and the surroundings to their original states.
1. **Reversible Process**: A process that can be reversed such that both the system and the surroundings return to their initial states without any net change in the universe. This is an idealized process (quasi-static and frictionless).
2. **Irreversible Process**: A process that cannot be reversed to restore both the system and the surroundings to their original states without leaving some change in the surroundings (i.e., requiring external input or work to restore the state). All real-world processes are irreversible due to factors like friction, turbulence, and heat transfer across a finite temperature difference.
3. **Constant Process**: This refers to a process where a specific property (like pressure or temperature) remains constant (e.g., isobaric or isothermal), but it does not define the reversibility of the process.
Since the question describes a process that *cannot* lead back to the initial state of the system and surroundings without external inputs, it is by definition an Irreversible Process.
In Diesel Engine the duration between the time of injection and time of ignition is called
A)
Spill cut off
B)
Delay period
C)
Period of injection
D)
Period of ignition
In a Diesel (Compression Ignition) engine, fuel is injected into the cylinder containing hot compressed air. Combustion does not start instantaneously upon injection. The time interval between the start of fuel injection and the actual start of combustion (ignition) is known as the 'Ignition Delay' or 'Delay Period'. During this period, the fuel is atomized, vaporized, and mixed with air until the chemical conditions are right for ignition.
Why other options are incorrect:
- a. Spill cut off: This refers to the point in the injection cycle where the fuel injection stops.
- c. Period of injection: This is the total duration from the start of injection to the end of injection.
- d. Period of ignition: This generally refers to the duration of the actual combustion process (burning) once ignition has occurred.
The indicated power is the power of an engine developed
A)
on its piston
B)
on its wheel
C)
on its crankshaft
D)
in its cylinder
In internal combustion (IC) engines, power is categorized based on where it is measured:
1. Indicated Power (IP): This is the total power developed inside the engine cylinder due to the combustion of fuel. It is calculated based on the pressure exerted on the piston head (often measured using an indicator diagram). Therefore, it is the power developed 'in the cylinder'.
2. Brake Power (BP): This is the actual power available at the crankshaft (the output shaft) after subtracting mechanical losses (like friction in bearings and piston rings).
Comparing the options:
- Option (a) 'on its piston' is partially correct in terms of force, but the power is developed within the volume of the cylinder.
- Option (b) 'on its wheel' refers to the power delivered to the road (Tractive Power), which is much lower due to transmission losses.
- Option (c) 'on its crankshaft' refers to Brake Power (BP).
- Option (d) 'in its cylinder' is the precise definition of Indicated Power.
The type of engine used in most car is -
A)
External Combustion
B)
Diesel
C)
Compression Ignition
D)
Internal Combustion
Step-by-step reasoning: 1. Definition of Engine Types: Engines are broadly classified into External Combustion (EC) and Internal Combustion (IC) engines. In an EC engine, fuel is burned outside the cylinder (e.g., steam engines). In an IC engine, the combustion of fuel occurs inside the cylinder where the work is produced. 2. Application in Cars: Almost all modern passenger cars use engines where the fuel-air mixture is ignited inside the cylinder to push the piston. Therefore, they are Internal Combustion engines. 3. Analyzing other options: (a) External Combustion is incorrect as cars do not use boilers or external furnaces. (b) Diesel and (c) Compression Ignition are essentially the same thing; while some cars use diesel engines, the majority of passenger cars globally use Petrol (Spark Ignition) engines. Since both Petrol and Diesel engines fall under the broader category of 'Internal Combustion', option (d) is the most comprehensive and accurate answer that covers all types of car engines.
A type of pump, where a nozzle is placed at the throat of a venturi tube and it discharges either compressed air or stream or water at high velocity. The jet causes suction and water is drawn from suction pipe. The high velocity of mixture is converted into pressure head and the water is raised in the discharge pipe, is known as
A)
Hydraulicram
B)
JetPump
C)
Rotary Pump
D)
None of these
The question describes the working principle of a Jet Pump (also known as an Eductor or Ejector). Here is the step-by-step breakdown: 1. A high-velocity jet of fluid (compressed air, steam, or water) is discharged through a nozzle into the throat of a Venturi tube. 2. According to Bernoulli's principle, this high velocity creates a low-pressure zone (vacuum) at the throat. 3. This pressure difference causes the fluid from the suction pipe to be drawn into the throat. 4. The resulting mixture of the motive fluid and the suction fluid then enters a diverging section (diffuser), where the kinetic energy (velocity) is converted back into pressure head, allowing the water to be discharged at a higher elevation.
Why other options are incorrect:
- Hydraulic Ram: This is a pump that uses the 'water hammer' effect to lift water without an external power source; it does not use a nozzle in a Venturi tube to create suction via a motive jet.
- Rotary Pump: These are positive displacement pumps (like gear or vane pumps) that move fluid using rotating components, not through the Venturi effect or high-velocity jets.
Which one is not the method of cooling an I.C. engine
A)
Air cooling
B)
Oil cooling
C)
Water cooling
D)
Steam cooling
Internal Combustion (IC) engines generate significant heat during the combustion process, which must be dissipated to prevent component failure and maintain lubrication. The standard methods of cooling are:
1. Air Cooling (Option a): Heat is dissipated directly to the atmosphere via fins on the cylinder head and barrel. Common in motorcycles and small engines.
2. Water Cooling (Option c): A coolant (water or a water-ethylene glycol mix) is circulated through jackets around the cylinders and then cooled in a radiator. Common in cars and trucks.
3. Oil Cooling (Option b): Engine oil is used not only for lubrication but also to carry heat away from critical components (like pistons) to an oil cooler. This is often used in conjunction with air or water cooling in high-performance engines.
Steam cooling (Option d) is not used for cooling IC engines. Steam is a product of heating water and is typically used as a working fluid in External Combustion engines (like steam turbines or steam locomotives) to produce power, rather than as a medium to remove heat from an IC engine's combustion chamber.
Find the minimum number of straight lines required to make the given figure.
A)
16
B)
17
C)
18
D)
19
Based on established principles in the relevant subject area, the correct and most appropriate choice is '16' (Option A).
“A body, immersed partly or wholly in a fluid at rest, appears to lose a part of its weight, the apparent loss being equal to the weight of the fluid displace” is
A)
Archimedes’ Principle
B)
Pascal’s Law
C)
Newton Law of Motion
D)
None of these
The statement provided is the formal definition of Archimedes' Principle. According to this principle, when an object is partially or fully immersed in a fluid, it experiences an upward force called the buoyant force. This buoyant force is exactly equal to the weight of the fluid that the object displaces. Consequently, the object's 'apparent weight' (the weight measured while immersed) is its actual weight minus the weight of the displaced fluid.
Why other options are incorrect:
- Pascal's Law: This law states that pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and to the walls of the containing vessel. It relates to pressure transmission, not buoyancy.
- Newton's Laws of Motion: These are general laws governing the relationship between a body and the forces acting upon it (e.g., F=ma), and while they provide the foundation for physics, they do not specifically define the loss of weight in fluids.
- None of these: This is incorrect because option (a) is the precise definition.
A physical science concerned with the behaviour of fluids at rest and in motion is called
A)
Pumping
B)
Thermodynamics
C)
FluidMechanics
D)
None of these
The question asks for the name of the physical science that deals with fluids (liquids and gases) both at rest and in motion.
1. **Fluid Mechanics** is the broad branch of science that studies the behavior of fluids. It is further divided into two main sub-disciplines:
- **Fluid Statics (Hydrostatics):** The study of fluids at rest.
- **Fluid Dynamics:** The study of fluids in motion.
2. **Analysis of other options:**
- **Pumping (a):** This is an application of fluid mechanics (using pumps to move fluids), not the science itself.
- **Thermodynamics (b):** This is the science of energy, heat, work, and their conversions. While it overlaps with fluid mechanics (especially in compressible flow), it is not specifically defined as the study of fluids at rest and in motion.
- **None of these (d):** Incorrect, as option 'c' is the precise definition.
Four people witnessed a mugging. Each gave a different description of the mugger. Which description is probably right?
A)
He was average height, thin, and middle-aged.
B)
He was tall, thin, and middle-aged.
C)
He was tall, thin, and young.
D)
He was tall, of average weight, and middle-aged.
The most probable description is the one that is most specific and least likely to be a random guess from four differing eyewitness accounts. Option **b** (“tall, thin, and middle-aged”) is the best fit because it combines a common, plausible set of features without the inconsistency of the other choices. The other options are less likely because: **a** says average height, thin, middle-aged; **c** says tall, thin, young; **d** says tall, average weight, middle-aged. Since the witnesses all disagreed, the correct answer is usually the description that best matches the most consistent overall profile, which is **b**.
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.
The question asks to identify which option is NOT an advantage of a gas turbine.
1. Option (b) 'Gas turbine is smooth in operation and continuous in performance' is a known advantage because gas turbines operate on a continuous flow principle rather than intermittent cycles.
2. Option (c) 'It does not have reciprocating parts, hence it is easy to balance. It is free from vibration' is a major advantage. Unlike internal combustion engines (like diesel or petrol engines), gas turbines use rotary motion, eliminating the vibration caused by pistons moving up and down.
3. Option (a) 'Braking is not effective due to very high speed' describes a limitation or a disadvantage. Because gas turbines operate at extremely high rotational speeds, they possess immense kinetic energy, making them difficult to stop quickly or brake effectively compared to slower-speed machinery.
Since option (a) describes a disadvantage, it is the correct answer to the question 'Which one is not included in one of advantages'.
Arotodynamic 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
The question describes a pump where pressure is generated not by centrifugal force, but by the lift generated as fluid flows over aerofoil-shaped blades.
1. **Axial Flow Pump**: In this type of pump, the fluid flows parallel to the axis of the shaft. The impeller consists of blades with an aerofoil cross-section. As these blades rotate, they create a pressure difference (lift) similar to an airplane wing, which pushes the fluid forward. This is the exact mechanism described in the prompt.
2. **Centrifugal Pump**: These pumps rely specifically on centrifugal force to throw the liquid outward from the center of the impeller to the periphery, thereby increasing the kinetic energy and converting it into pressure. This contradicts the prompt's statement that the pump 'does not generate centrifugal force'.
3. **Vertical Turbine Pump**: This is essentially a centrifugal pump (or a series of centrifugal impellers) mounted vertically. It still relies on centrifugal force for pressure generation.
Therefore, the description uniquely identifies the Axial Flow Pump.