HPCL Mechanical Engineer Mock Test - 5 - Mechanical Engineering MCQ

feasible : that is possible and likely to be achieved

To lynch is to murder, or unlawfully kill. When an angry mob kills someone they believe is guilty of a crime, they lynch that person. Through history, when a group of people murders someone, especially by hanging him by the neck, they are usually said to lynch him.

Initial number of balls = 90 + 110 + 150 + 50 = 400
Balls removed = 50% of 90 + 70% of 110 = 122
Remaining balls = 278

Hence, Option D is correct.

( x=0.222)-eq1
(10x=2.22 after multiplying 10 to both side)-eq2
(9x=2after subtract eq2 from 1)
x= 2/9
we have find 9x so,
9×(2/9)
9×2/9
2

Expenditure : Savings = 100 : 125 = 4 : 5

Hence, Option C is correct.

Hence, Option A is correct.

Hence, Option D is correct.

Following the common explanation, we get “7 seats are there to the left of C”.
Hence, option D is correct.
Final Arrangement:

Common Explanation:
References:
1. Two people are sitting between A and Z.
2. C sits fourth to the right of Z.
3. The number of people sitting to the right of A is the same as the number of people sitting to the left of Z.
4. The number of people sitting between A and C is the same as the number of people sitting between X and C.
5. X is an immediate neighbour of D, who sits on one of the ends.
6. The number of people sitting between D and C is the same as the number of people sitting between C and Y.
7. At most 25 people are sitting in a row.
Inferences:
From reference 1, we get two possible cases.
From reference 7, case2 was eliminated.
Hence, Case 1 is the final arrangement.

All these are used for broadcast.

Given:

Length of rectangle = 3/5 of radius of circle

Radius of circle = Side of square with area 6400 m2

Breadth of rectangle = 15 m 

Formulas used:

Area of square = (Side)²

Perimeter of rectangle = 2(Length + Breadth) 

Calculation:

Area of square = 6400 m2

⇒ Side² = 6400 

⇒ Side = √6400 = 80 m 

Radius of cirlce = Side of square = 80 m 

⇒ Length of rectangle = 3/5 × 80 = 48 m 

∴ Perimeter of the rectangle = 2(48 + 15) m 

⇒ 126 m 

All except White are colours of the' rainbow.

1st term = 1
2nd term = 3
3rd term = 4
4th term = 1 + 3 + 4 = 8
5th term = 3 + 4 + 8 = 15
6th term = 4 + 8 + 15 = 27

Thus, the missing term is 7th term = 8 + 15 + 27 = 50

Checking Statement I:

Using the above references, we get the following cases:

Case 1:

Case 2:

 Since there is no clear information about the position of Ramesh so, we cannot say anything about the person who sits on the immediate left of Ramesh.

Clearly, Statement I alone is not sufficient to answer the question.

Statement II:

Using the above references, we get the following cases:

 
Clearly, Statement II alone is not sufficient to answer the question.

Checking both statements I and II:

Using the both statements, we get the following arrangement:

Clearly, Both statement I and II are sufficient to answer the question.

Hence, Option D is correct.

As the sound of 'Jackal' is 'Howl' similarly the sound of 'Cow' is 'Moo'.

When the relative humidity of the air is 100%, i.e, the air is saturated, the dew point temperature (DPT) equals the wet-bulb temperature (WBT), which is also equal to the dry-bulb temperature.

So DBT = WBT = DPT

For unsaturated air:

DBT > WBT > DPT

- A body is said to be in equilibrium when it comes back to its original position after it is slightly displaced from its position of rest. In general, the following are the three types of equilibrium :

Stable equilibrium:

- A body is said to be in stable equilibrium if it returns back to its original position after it is slightly displaced from its position of rest

- This happens when some additional force sets up due to displacement and brings the body back to its original position

A smooth cylinder, lying on the curved surface, is in stable equilibrium

Unstable equilibrium

- A body is said to be in unstable equilibrium if it does not return back to its original position and heels farther away after slightly displaced from its position of rest

- This happens when the additional force moves the body away from its position of rest

- A smooth cylinder lying on a convex surface

Neutral equilibrium

- A body is said to be in neutral equilibrium if it occupies a new position (and remains at rest in this position) after slightly displaced from its position of rest

- This happens when no additional force sets up due to the displacement

- A smooth cylinder lying on a horizontal plane is in neutral equilibrium

Concept:

E = Young's Modulus of elasticity = Stress / strain

G = Shear Modulus or Modulus of rigidity = Shear stress / Shear strain

ν = Poisson’s ratio = - lateral strain / longitudinal strain

K = Bulk Modulus of elasticity = Volumetric stress / Volumetric strain

Relation between E, K and ν

E = 2G (1 + ν)

E = 3K (1 - 2ν)

Calculation:

E = 3K (1 - 2ν)

dV = 0.2%

Compressibility (β) =

Austenite→ Ferrite + Cementite is the example of a Eutectoid reaction

A eutectoid reaction is a three-phase reaction by which, on cooling, a solid transforms into two other solid phases simultaneously. If the bottom of a single-phase solid field closes (and provided the adjacent two-phase fields are solid also), it does so with a eutectoid point.

Concept:

The difference between the maximum and minimum speeds during a cycle is called the maximum fluctuation of speed. The ratio of the maximum fluctuation of speed to the mean speed is called the coefficient of fluctuation of speed (Cs).

Calculation:

ω_max – ω_min = ± 2% of ω_mean

⇒ ω_max – ω_min = 4% of ω_mean⇒ ω_max – ω_min = 0.04 ω_mean

⇒

Correct Answer :- b

Explanation : The Soderberg line is a more conservative failure criterion and there is no need to consider even yielding in this case.

- Viscosity is the most important property of lubricating oil. It is a measure of its internal friction or resistance to flow.

- It provides a measure of the thickness of lubricating oil at a given temperature; the higher the viscosity, the thicker the oil.

An isentropic process is also known as a reversible adiabatic process.

If the process is reversible and adiabatic: dQ_rev = 0 ⇒ dS = 0

Entropy analysis for a closed system:

Case 1: For an internally reversible process (δs)_gen = 0

When heat is added to the system ⇒ (δQ) = +ve ⇒ ds = +ve

When heat is rejected from the system ⇒ (δQ) = -ve ⇒ ds = -ve

For adiabatic process ⇒ (δQ) = 0 ⇒ ds = 0 (ISENTROPIC)

Case 2: For internally irreversible process (δs)gen ≠ 0 ⇒ (δs)gen = +ve

When heat is added to the system ⇒ (δQ) = +ve ⇒ ds = +ve

When heat is rejected from the system ⇒ (δQ) = -ve ⇒ ds = -ve or +ve or zero

​Since (δs)_gen = +ve and (δQ) = -ve so change in entropy, ds can be zero is (δQ/T) = δs)gen. In this case, the process will be ISENTROPIC

For adiabatic process ⇒ (δQ) = 0 ⇒ ds = +ve

Thus for a process to be isentropic, there are two cases:

Reversible adiabatic process

The irreversible process where (δQ/T) = δs)gen

Note: Irreversible adiabatic process is not an isentropic process.

Stress = force per unit area, i.e. F / A or N/m²

Strain = change in length per unit original length, i.e. m/m or mm/mm.

Hooke’s Law holds good up to the proportional limit.

According to Hooke’s Law, stress is directly proportional to strain within the elastic limit.

Note: Stress is not pressure per unit area because pressure itself is force per unit area.

R₁ + R₂ = P

R₂ × L = P × L/4

R₂ = P/4

R₁ = 3P/4

Bending moment at the point of applied load:

Boiler accessories are those components that are installed either inside or outside the boiler to increase the efficiency of the plant and to help in the proper working of the plant.

Various boiler accessories are:

1) Air Preheater

2) Economizer

3) Super-heater

4) Feed Pump

5) Injector

Boiler mountings are the machine components that are mounted over the body of the boiler itself for the safety of the boiler and for complete control of the process of steam generation.

Various boiler mountings are as under:

1) Pressure gauge

2) Water Level Indicator

3) Fusible plug

4) Safety Valve

i) Lever Safety Valve

ii) Spring Loaded Safety Valve

5) Steam stop valve

6) Feed check valve

7) Blow off cock

Actually, there is a distinct difference between heat and temperature.

Temperature is a measure of the amount of energy possessed by the molecules of a substance. It manifests itself as a degree of hotness and can be used to predict the direction of heat transfer. The usual symbol for temperature is T. The scales for measuring temperature in SI units are the Celsius and Kelvin temperature scales.

Heat, on the other hand, is energy in transit. Spontaneously, heat flows from a hotter body (higher temperature) to a colder one (lower temperature). The usual symbol for heat is Q. In the SI system, common units for measuring heat are the Joule and calorie.

Confusion point:

There are different types of energy. Heat is a transfer of thermal energy.

The driving force for heat transfer is the temperature difference.