HPCL Mechanical Engineer Mock Test - 3 - Mechanical Engineering MCQ

In the given context we are talking about the way in which he convinced his parents for the school trip and since he did it very quickly, it is evident that it was a very easy thing to do by his standard.

A Stalking horse: Pretence 
A slap on the wrist: A very mild punishment 
A piece of cake: Something that is very easy to achieve 
A toss-up: An uncertain result that can go either way 
Among the given options, it is clear that option C is correct in the given context as it expresses the actual meaning of the given context.
This makes option C the correct choice among the given options.

(25)^1/3=(5²)^1/3=(5)^2/3
5^2/3x5^1/3=5^3/3=5¹  when multiplied [ power are added ]
so answer is 5

Since A, B and C are the angles of a Δ,
∴ A + B + C = 180° .................... (1)
According to question,
A – B = 15° ;
⇒ A = B + 15°...................(2)
B – C = 30°;
⇒ B = C + 30°;....................(3)
Put the value of B from equation (2) in Equation (1), we will get
∴ A = B + 15°
A = C + 30° + 15°
A = C + 45° ......................(4)
From a equation,
∴ A + B + C = 180°
⇒ (C + 45°) + (C + 30°) + C = 180°
⇒ 3C + 45° + 30° = 180°
⇒ 3C = 180° – 75° = 105°
⇒ C = 35° ...........................(5)
From equation (4)
A = C + 45°
Put the value of C from equation (5) , we will get
∴ ∠A = 35° + 45° = 80°.

Hence, Option D is correct.

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

Volume of the cuboid = L * B * H 
V = 4cm * 2cm * 3cm
V = 24 cm³ 
Hence the option A is correct.

The logic follows here is :-

From the given words we can understand that it is a process of construction or a materials.

Planning → Designing → Implementation → Manufacturing → Production 

So, logical and meaningful order is 4 - 1 - 5 - 2 - 3

Thus, the correct answer is "4 - 1 - 5 - 2 - 3".

‘Knife’ is related to ‘Cut’, means we use knife for cutting.

Similarly,

We use pen for writing.

Hence, Write is the correct answer.

As Ornithologist is a specialist of Birds similarly Archealogist is a specialist of Archealogy.

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:

Hence, option D is correct.

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

Atom

An atom is the smallest particle of an element, having the same chemical properties as the bulk element. The first accurate theory explaining the nature of matter was Dalton's Atomic Theory: 1. All matter is composed of atoms, and atoms are indivisible and indestructible.

Example to fire tube boilers:

• Cornish boiler

• Cochran boiler

• Locomotive boiler

• Lancashire boilerScottishh marine boiler

Water Tube Boiler: In this boiler, water is present inside the tubes, and the hot flue gases surround them. They are high-pressure boilers. The operating pressure is about 250 bar.

Examples of water tube boilers:

• Stirling boiler

• Babcock and Wilcox boiler

• Yarrow boiler

• La mont boiler

• Loeffler boiler

• Velox boiler

Types and importance of polarity in arc welding

Polarity indicates the direction of current flow in the welding circuit.

Kinds of polarity

• Straight polarity or electrode negative (DCEN)
• Reverse polarity or electrode positive (DCEP)

Straight polarity: In straight polarity, the electrode is connected to the negative and the work to the positive terminal of the power source.

Electrode Negative Or straight polarity (DCEN)

Reverse Polarity: In reverse polarity, the electrode is connected to the positive and the work to the negative terminal of the power source.

Electrode Positive Or Reverse Polarity (DCEN)

DCSP (Electrode Negative)—Maximum penetration.

AC—Moderate penetration.

DCRP (Electrode Positive)—Minimum penetration

Taking log

log(p_2/p₁)/log(v₁/v₂)

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

The working of the venturi meter is based on the principle of Bernoulli’s equation.

The Venturi meter is divided into 3 parts:

1. Convergent cone

2. Divergent cone

3. Throat

Important Point:

Convergent cone:

The angle of convergence is generally 20-22 degrees.

The length of the convergent cone is 2.7(D-d).

Here 'D' is the diameter of the inlet section, and 'd' is the diameter of the throat.

Throat:

The length is equal to the diameter of the throat.

Generally, the diameter of the throat is 1/3 to 3/4 of the diameter of the inlet pipe.

Diverging cone:

The diverging section has an angle of 5 to 15 degrees.

The diverging angle is less than the converging angle.

Although the desirable ratio of throat diameter and pipe diameter lies between 1/3 to 3/4.

The most appropriate option is 0.33 to 0.5, as the energy losses would minimize if the area difference is minimized.

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.

Metals: Iron, lead, gold, aluminium, platinum, uranium, zinc, lithium, sodium, tin, silver, etc.

Non-Metals: Hydrogen, helium, carbon, sulphur, nitrogen, oxygen, radon, neon, other halogens, and noble gases, etc.

Alloys such as medium and high carbon steel, cast iron, and tool steel are brittle. Metals like gold, copper, lead, and silver are the opposite - ductile.

Where H is a totally effective head.

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

F is the frictional force developed, and N is the normal reaction.

The direction of resultant R measured from the direction of N is specified by tan θ = F/N

μ = tanθ = F/N

Here F = R sin θ

N = R cos θ

Where θ is angle of friction.

Undercutting/Grooving is the process of reducing the diameter of a workpiece over a narrow surface.

Knurling is an operation of embossing a diamond-shaped pattern on the surface of a workpiece.

Chamfering is the operation of bevelling the extreme end of a workpiece. It is used to remove the sharp edge of the workpiece surface.

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.)

The efficiency by which they do so is measured in terms of "thermal efficiency,” and most gasoline combustion engines average around 20 percent thermal efficiency. Diesel engines are typically higher--approaching 40 percent in some cases.

A thermistor, derived from the term thermally sensitive resistors, is a very accurate and cost-effective sensor for measuring temperature. It is available in 2 types, NTC (negative temperature coefficient) and PTC (positive temperature coefficient); it is the NTC thermistor that is commonly used to measure temperature.

Dry Bulb Temperature: Actual temperature of gas or mixture of gases.

Wet-bulb temperature: Temperature obtained by an accurate thermometer having a wick moistened with distilled water.

Dew point temperature: Temperature at which the liquid droplets just appear when the moist air is cooled continuously.

Sensible heating: Moisture content of air remains constant, so specific humidity is constant, temperature increases as it flows over a heating coil.

Sensible cooling: The moisture content of air remains constant, so specific humidity is constant, but its temperature decreases as it flows over a cooling coil.

According to the question:

If air is heated without changing its moisture content, ⇒ Sensible heating.

Sensible heating: It is the process of increasing the Dry bulb temperature at a constant specific humidity.

Effects of sensible heating:

• Dry bulb temperature increases
• Sp. Humidity or humidity ratio remains constant
• Dew point temperature is constant
• Relative humidity decreases
• Enthalpy increases
• Specific Volume Increases
• Wet-bulb temperature increases