HPCL Mechanical Engineer Mock Test - 8 - Mechanical Engineering MCQ

The word maraud comes from a Middle French word that means "rascal or rogue."

 A marauder is someone who marauds and marauding describes people who raid and plunder. As a noun, a maraud is a quick, short foray. 

Use structure “subject + auxiliary + past participle + by + object”
As per the given above sentence is given in Passive Voice.
The wounded woman was being helped by some people.
Therefore ,required answer will be option B .

The word Hasten (Verb) means : hurry; to say or do something without delay.
The word Dawdle (Verb) means : to take a long time to do something or go somewhere. 

As per the meanings given below, the correct idiom will be ‘playing devil’s advocate’.
Take a rain check: postpone a plan.
Rain on someone’s parade: to spoil a moment.
Play devil’s advocate: to argue, just for the sake of it.
Play by the ear: to improvise.
Correct Sentence:
He was not agreeing to back off, as if he was playing devil’s advocate.
Hence, the correct answer is option C. 

The original sentence is in the active voice: "Do not disturb the patient."

The best expression of this sentence in the passive voice is: "The patient is not to be disturbed."

Therefore, the correct answer is indeed option B: "The patient is not to be disturbed."

Since, 5 and 8 are the remainders of 70 and 125, respectively. Thus, after subtracting these remainders from the numbers, we have the numbers 65 = (70-5),
117 = (125 – 8), which is divisible by the required number.
Now, required number = HCF of 65,117                                     [for the largest number]
For this, 117 = 65 × 1 + 52 [∵ dividend = divisior × quotient + remainder]
⇒ 65 = 52 × 1 + 13
⇒ 52 = 13 × 4 + 0
∴ HCF = 13 
Hence, 13 is the largest number which divides 70 and 125, leaving remainders 5 amnd 8.

Total time taken = (160/64) + (160/80) = 9/2 hrs
∴ Average speed = 320 x (2/9) = 71.11 km/hr.

Total Mango trees = 40%

Remaining trees = (100 – 40 – 50)% = 10%

Hence, Option B is correct.

Hence, Option B is correct.

To find the product of 7/8 and -4/21, follow these steps:

• Multiply the numerators: 7 × -4 = -28.
• Multiply the denominators: 8 × 21 = 168.
• Combine the results: -28/168.
• Simplify the fraction: -28/168 can be reduced to -1/6.

The final answer is -1/6.

Let the measured of the required angle be P degree.
Then, its supplement = 180 – P
Now use the formula,

3P + P180°
⇒ P = 45°

In the given coding system, we have:

So, the code for BOIL is 5, 31, 19, 25.
Hence, option D is correct.

∴ STOLL → $2@33
Hence, option B is correct.

The logic follows here is :

Sum of place values of alphabets of the given word = Given number.

MONK → M + O + N + K = 13 + 15 + 14 + 11 = 53.

Similarly,

TUTOR → T + U + T + O + R = 20 + 21 + 20 + 15 + 18 = 94.

Hence, the correct answer is "94".

The logic followed is:

Similarly,

Hence, the correct answer is "15".

The number of instantaneous centres in a constrained kinematic chain is equal to the number of possible combinations of two links.

The number of instantaneous centres:

where n is the number of links.

Carburization is a heat treatment process in which iron or steel absorbs carbon. In contrast, the metal is heated in the presence of a carbon-bearing material, such as charcoal or carbon monoxide. The intent is to make the metal surface harder.

Proof resilience is defined as the maximum energy that can be absorbed within the elastic limit without creating a permanent distortion.

The modulus of resilience is defined as the maximum energy that can be absorbed per unit volume without creating a permanent distortion (i.e., The proof resilience per unit volume of a body is called the modulus of resilience). It can be calculated by integrating the stress-strain curve from zero to the elastic limit.

The area up to the Elastic limit is termed the modulus of resilience, and the total area up to fracture is termed the modulus of toughness.

Calculation:

Modulus of resilience = Area under stress-strain graph up to an elastic limit

= 1/2 × 2 × 10⁻³ × 350 = 0.35;MPa = 350;kPa

P= Pitch

d= depth of thread

r= radius at crest and root

A Stirling cycle consists of two reversible isothermal and two reversible constant volume (isochoric) processes.

ηStirling = T₃/T₁/T₃

Which is the same as Carnot’s efficiency.

Whereas an Ericsson cycle consists of two reversible isothermal and two reversible constant pressure (isobaric) processes.

ηericsson = 1−T₁/T₃which is the same as Carnot efficiency

Hence, the correct option is (C).

Hematite

Hematite and magnetite are by far the most common types of ore. Pure magnetite contains 72.4 percent iron, hematite 69.9 percent, limonite 59.8 percent, and siderite 48.2 percent, but since these minerals never occur alone, the metal content of real ores is lower.

Pure torsion will be the case of pure shear in which principal normal stresses occur 45° to the axis.

Maximum and minimum principal stresses are equal in magnitude and opposite in direction.

2θ₁ = 90° ⇒ θ₁ = 45°

Correct Answer :- D

Explanation : The process of preheating involves heating the area around the weld joint or the entire part to a specified temperature before welding. This reduces the cooling rate of the weld and drives out moisture, which in turn helps prevent hydrogen buildup and the potential for cracking.