HPCL Mechanical Engineer Mock Test - 3 Free Online Test 2026

Let us first learn the meanings of the given words:

Reverberate (verb): be repeated several times.

Echo (verb): repeat (someone's words or opinions), typically to express agreement.

Resonate (verb): to produce or be filled with clear, continuing sound.

The idea here is to express that the end of FTX is a continuous topic of discussion, thus all the options are apt contextually and grammatically.

Hence, the correct answer is option C.

Factoring √12 and √27 and solving, we get
√12 = √(4 x 3) = √(2 x 2 x 3) = 2√3
√27 = √(9 x 3) = √(3 x 3 x 3) = 3√3

Now the equation we get is 3√12 / 6√27. On substituting the values from above, we get

Given, 3, 8, 13, 18, … is the AP.
a = 3
d = a(2) – a(1) = 8 − 3 = 5
Let a(n) term be 78.
a(n) = a + (n − 1) x d
78 = 3 + (n − 1) x 5
75 = (n − 1) x 5
(n − 1) = 15
n = 16

Efficiency → A : B = 75 : 100 = 3 : 4

Hence, Option C is correct.

Only daughter of woman’s father is woman herself. So, the woman is person’s mother.

• 9 (3²) : 8 (2³)

• 16 (4²) : 27 (3³)

The pattern is: n² : (n-1)³.
So, for 16 (4²), the missing number is 3³ = 27.

Final Answer: a) 27

From the common explanation, we get the position of O is 3rd to the left of M.

Hence, Option B is correct.

Final Arrangement:

Common Explanation:

References:

J sits fourth to the right of O and N sits second to the left of J.

Only H sits between J and G.

Inferences:

From the above references, we get

References:

Only D sits between G and C

G is not an immediate neighbour of J but fifth to the right of I.

M, who sits exactly in the middle, is second to the right of I.

Five persons sit between L and J.

Inferences:

From the above references, we get

References:

E is not an immediate neighbour of N.

Inferences:

From the above reference, we get the final arrangement:

Checking Statement I:

Using the above references, we get the following arrangement:

Clearly, W is sitting at the right end.

Hence data in statement I is sufficient to answer the question.

Checking Statement II:

Using the above references, we get the following different arrangement:

Thus we cannot find the final conclusion.

Hence data in statement II is not sufficient to answer the question.

Hence, Option A is correct.
 

Checking Statement I:

Using the above references, we get the following arrangement:

Kamal > Rohit > Priya/Johny > Suresh > Tinku

Clearly Kamal is the oldest among all.

Hence data in statement I is sufficient to answer the question.

Checking Statement II:

Using the above references, we get the following arrangement

Kamal > Priya > Suresh > Johny > Tinku > Rohit

Clearly Kamal is the oldest among all.

Hence data in statement II is sufficient to answer the question.

Here, the data in either Statement I or II alone is sufficient to answer the question.

Hence, Option C is correct.

As 'Much' corresponds to 'Many' in the same way 'Measure' corresponds to 'counting'.

Angle of Friction between any two surfaces in contact is defined as the angle which the resultant of the force of limiting friction Film and normal reaction N makes with the direction of normal reaction N.

tanθ = F_lim/N = μ

The angle of repose or angle of sliding α is defined as the minimum angle of inclination of a plane with the horizontal such that a body placed on the plane just begins to slide down.

f = mg sin α

N = mg cos α

tan α = f/N

tan α = tan θ

α = θ

∴ The angle of friction = Angle of repose

Turbine work = Area under curve R-S = Area of Rectangle + Area of the shaded region.

W = (0.2 – 0.1) × 1 × 10⁵ + 1000

W = 11000 N – m

Main parts of Lathe:

A critical path is a sequence of interdependent activities or tasks, and it is the longest path (i.e., the path with the longest duration) from project start to finish. At the same time, the longest path is the path that shows the shortest possible length of time in which the project can be completed.

Boiler Economiser ( Sometimes Called Economizer ) is the Energy improving device that helps to reduce the cost of operation by saving the fuel. In boilers, economizers are generally Heat Exchangers which are designed to exchange heat with the fluid, generally water.

The numerical value of the slope of an isenthalpic on a T-p diagram at any point is called the Joule-Thomson coefficient and is denoted by μ_j

A measure of the change in temperature results from a drop in pressure across the construction.

If μ is +ve, then the temperature will fall during throttling.

So from the figure, it is clear that temperature may increase or decrease it will depend on the value of μ.

Methods of elimination of Gear tooth Interference:

• Use of a larger pressure angle (having a larger pressure angle results in a smaller base circle. As a result, more of the tooth profiles become involute)

• Under-cutting of the tooth (A portion of teeth below the base circle is cut off. When teeth are produced by this process, the tip of one tooth of gear will not contact the non-involute portion of the tooth of other gear)

• Tooth stubbing (In this process, a portion of the tip of the teeth is removed, thus preventing that portion of the tip of the tooth from contacting the non-involute portion of the other meshing tooth).

• Increasing the number of teeth on the gear can also eliminate the chances of interference.

• Increasing the center distance between the meshing gears slightly eliminates interference.

• Tooth profile modification or profile shifting (Using profile shifted gears (gears with non-standard profile) can also be an option to eliminate interference. In profile shifted meshing gears, the addendum on the pinion is shorter compared with standard gears).

Where H is a totally effective head.

P = 1000 × 0.1 × 9.81 × (10 + 5) = 14715 W = 14.7 kW

A tire-pressure gauge, or tyre-pressure gauge, is a pressure gauge used to measure the pressure of tires on a vehicle. Since tires are rated for specific loads at a certain pressure, it is important to keep the pressure of the tire at the optimal amount.

Refrigeration circuit: Ammonia as working medium (primary refrigerant) produces the cold by changing its phase at different locations.

Cooling water circuit: Cooling water as a working medium to remove the heat of the condenser.

Brine circuit: Brine solution as a working medium which transfers the cold from ammonia to water-filled cans where ice is to be formed.

The equation form of Newton's second law allows us to specify a unit of measurement for the force. Because the standard unit of mass is the kilogram (kg) and the standard unit of acceleration is meters per second squared (m/s²), the unit for force must be a product of the two -- (kg)(m/s²).

Basic Principle of Hot Wire Anemometer

When an electrically heated wire is placed in a flowing gas stream, heat is transferred from the wire to the gas, and hence the temperature of the wire reduces, and due to this, the resistance of the wire also changes. This change in opposition of the wire becomes a measure of flow rate.

∴ A hot wire anemometer is used to measure the velocity of the fluid.

Completely constrained motion is a type of constrained motion in which relative motion between the links of a kinematic pair occurs in a definite direction by itself, irrespective of the external forces applied.

The law of the machine is (where P = Effort applied to lift the load, m = A constant which is equal to the slope of the line, W = Load lifted, and C = Another constant which represents the mechanical friction.)

Bernoulli's equation is applicable to venturimeter, orifice meter and pitit tube.

Since reciprocating mass cannot balance fully, partial balancing of the reciprocating mass is done while revolving masses can be balanced fully.

Primary unbalanced Force F_P = mrω²cos2θ

Secondary unbalanced Force = FS = mrω²cos2θ/n

Effect of Partial Balancing of Reciprocating Parts

Reciprocating parts are only partially balanced. Due to this partial balancing of the reciprocating parts, there is an unbalanced primary force along the line of stroke and an unbalanced primary force perpendicular to the stroke line. The effect of an unbalanced primary force along the line of stroke is to produce;

• Variation in tractive force along the line of stroke

• Swaying couple

The stiffness, k, of a body is a measure of the resistance offered by an elastic body to deformation. For an elastic body with a single degree of freedom (DOF) (for example, stretching or compression of a rod),

the stiffness is defined as

rm k = rmF/rmδ

where,

F is the force on the body

δ is the displacement produced by the force along the same degree of freedom

∴ The resistance of the material to deflection is known stiffness.