HPCL Mechanical Engineer Mock Test - 4 - Mechanical Engineering MCQ

The logic follows here is:

(Number)2 : (Number)3 :: (Number)2 : (?)3

49 : 343

(7)2 : (7)3 

Similarly,

121 : ?

(11)2 : (11)3 

121 : 1331

? = 1331

Hence, the correct answer is "1331".

These are all defensive games.

1st term = 12
2nd term = 12 + 20 = 32
3rd term = 32 + 40 = 72
4th term = 72 + 80 = 152

Thus, the missing term is 5th term = 152 + 160 = 312

The logic followed is:

Given code: "MANIPUR is written as NBOJQVS" 

Similarly,

Thus "PATTERN will be written as "QBUUFSO".

Hence, the correct answer is "QBUUFSO". 

The rating indicates the maximum capacity of a boiler. When a boiler operates at its maximum rated capacity, it is referred to as the maximum load. If the load varies from hour to hour, it operates at a varying load. Load and load variations can influence the amount of chemicals required for treatment and the treatment controls required.

As both are in parallel, therefore k_eq = k + k = 2k

(i) If velocity potential (ϕ) exists, the flow should be irrotational.

(ii) If velocity potential (ϕ) satisfies the Laplace equation, it represents the possible steady incompressible irrotational flow.

Stream function:

(i) If stream function (ψ) exists, the flow may be rotational or irrotational.

(ii) If stream function (ψ) satisfies the Laplace equation, it represents the irrotational flow.

Vorticity:

Defined as the value twice of the rotation

ζ=2ω

For an irrotational flow, vorticity components are zero

P + 1/2ρV² + ρgh = c

P is the pressure, r is the density, v is the velocity, h is the elevation difference.

The value of C in the above equation is constant only along a streamline and should essentially vary from streamline to streamline.

The equation can be used to define the relation between flow variables at point B on the streamline and at point A, along the same streamline. So, to apply this equation, one should have knowledge of the velocity field beforehand. This is one of the limitations of the application of Bernoulli's equation.

Therefore, the total mechanical energy remains constant everywhere in inviscid and irrotational flow, while it is constant only along a streamline for inviscid but rotational flow.

Any mixture greater than 14.7: 1 is considered a lean mixture, and less than 14.7: 1 is a rich mixture.

So the correct mixture ratio according to the given options will be 15: 1.

Mercury has a very low vapour pressure when compared to that of water. So, it is more sensitive than water to the changes in the atmospheric pressure and rises more quickly to record the changes in the atmospheric pressure.

Another ceramic tool material is silicon nitride.

Polygon Law of forces

It states that if a number of concurrent forces acting on a particle are represented in magnitude and direction by the sides of a polygon, taken in order, then their resultant is represented in magnitude and direction by the closing side of the polygon, taken in the opposite order.

A system of concurrent coplanar forces acting on a particle are:

(a) Given system (b) Resultant of given forces

The epicyclic gear trains are useful for transmitting high-velocity ratios with gears of moderate size in a comparatively lesser space. The epicyclic gear trains are used in the back gear of lathe, differential gears of the automobiles, hoists, pulley blocks, wristwatches, etc.

Flexible couplings are usually used to transmit torque from one shaft to another when the two shafts are slightly misaligned. They can accommodate varying degrees of misalignment up to 1.5° and some parallel misalignment. They can also be used for vibration damping or noise reduction.

p = ρgh

Pressure distribution profile

dp/dz = -ω = -pg

dp = -ω.dz

It indicates that a negative pressure gradient exists upward along any vertical.

Thus, the pressure decreases in the upward direction and increases in the downward direction with a magnitude equal to a specific weight.

As radiation is the mode of heat transfer in which heat is radiated or transmitted from one place to another in the form of rays or waves. It does not require any material medium. It takes place by electromagnetic radiation.

The unit of momentum is the product of the units of mass and velocity. In SI units, if the mass is in kilograms and the velocity is in meters per second, then the momentum is in kilogram meters per second (kg⋅m/s).

SI unit: kilogram meter per second kg⋅m/s

Objects moving in a uniform circular motion will have a constant speed. The magnitude of the velocity vector is the instantaneous speed of the object. The direction of the velocity vector is directed in the same direction that the object moves.

• Stable equilibrium : GM > 0 (M is above G)
• Neutral equilibrium : GM = 0 (M coinciding with G)
• Unstable equilibrium : GM < 0="" (m="" is="" below="" g)="" />

(a) Equilibrium Position (b)Tilted Position

Condition of stable equilibrium for a floating body in terms of centre of buoyancy and the centre of gravity:

• Stable equilibrium: If its centre of gravity is directly below the centre of buoyancy
• Neutral equilibrium: If its centre of gravity is coincident with the centre of buoyancy
• Unstable equilibrium: If its centre of gravity is directly above the centre of buoyancy

A submerged body is in equilibrium when the centre of gravity is located below the centre of buoyancy. If the body is tilted slightly in any direction, the buoyant force and the weight always produce a restoring couple trying to return the body to its original position.

COP = R.E/W

Relative Coefficient of performance: It is the ratio of the actual and theoretical coefficient of performance.

Energy Performance Ratio (EER) is the ratio of output cooling energy (in BTU) to electrical input energy (in Watt-hour).

Efficiency is the energy output, divided by the energy input

Gray cast iron is a broad term used for a number of cast irons whose microstructures are characterized by the presence of flake graphite in the ferrous matrix. Such castings often contain 2.5% to 4% carbon, 1% to 3% silicon, and some additions of manganese ranging from 0.1% to 1.2%.

Strain Energy of the member is defined as the internal work done in deforming the body by the action of externally applied forces.

Resilience is defined as the capacity of a strained body for doing work on the removal of the straining force.

Proof resilience is defined as the maximum strain energy stored in a body. So, it is the quantity of strain energy stored in a body when strained up to the elastic limit (ability to store or absorb energy without permanent deformation).

Modulus of resilience is defined as proof resilience per unit volume. It is the area under the stress-strain curve up to the elastic limit.

The modulus of toughness is the ability to absorb energy up to fracture. From the stress-strain diagram, the area under the complete curve gives the measure of modulus of toughness.

(Rate of mass efflux from control volume)-(Rate of mass flow into control volume)+(Rate of accumulation of mass within control volume) = 0

The net outward flow of mass across the control surface or the net mass efflux from the control volume:

The rate of accumulation of mass within the control volume:

Direction of flow→

Fluid flowing through a pipe

∴ The continuity for a steady flow that efflux rate of mass through the control surfaces is zero.

Vanadium:

• It has a marked effect on increasing the hardenability

• It inhibits grain growth when steel is heated at a high temperature

• It is a strong carbide former; Vanadium carbides possess the highest hardness and wear resistance

• It improves fatigue resistance (endurance strength)

• It is generally found in tool steels

Nickel:

• Nickel dissolves in ferrite, increasing hardness, strength, and toughness without sacrificing the ductility

• It increases the impact resistance of steel at a very low temperature

• A higher amount of nickel is added to increase the corrosion resistance of high chromium steels