RCFL MT Mechanical Mock Test - 10 - Mechanical Engineering MCQ

Punching/Blanking: Punching or blanking is a process in which the punch removes a portion of material from the larger piece or a strip of sheet metal. If the small removed piece is discarded, the operation is called punching, whereas if the small removed piece is the useful part and the rest is scrap, the operation is called blanking.

Piercing: It is a process by which a hole is cut (or torn) in metal. It is different from punching in that piercing does not generate a slug.

Perforating: It is an operation in which a number of uniformly spaced holes are punched in a sheet of metal. The holes may be of any size or shape. They usually cover the entire sheet of metal.

Nothing: It is an operation in which a specified small amount of metal is cut from the edges.

Lancing: It is an operation of cutting a sheet metal through a small length and then bending this cut portion.

The work done is said to be zero work when force and displacement are perpendicular to each other or when either force or displacement is zero. Example: When we hold an object and walk, the force acts in the downward direction, whereas displacement acts in the forward direction.

General gas equation

pv=mrt

at absolute zero kelvin temp.
pressure =zero

that means

0×v= mr×0

therefore volume will be zero at absolute zero kelvin temp.

If you use this value of R, then technically, the formula should be written as pV = mRT, where m represents the mass of air in kg (and we avoid having to do any calculations with moles.) Pressure is measured in Pascals (Pa), and 1 Pascal is defined as 1 N/m².

Coining is essentially a cold‐forging operation except that the flow of the metal occurs only at the top layers and not the entire volume. In the coining process, compressive forces are there.

In blanking, the piece being punched out becomes the workpiece, and any major burrs or undesirable features should be left on the remaining strip. Blanking is a shearing operation.

Drawing when cup height is more than half the diameter is termed deep drawing. During deep drawing, in the flange of blank, there is bi‐axial tension and compression stresses.

Law of limiting friction for dry surfaces:

• When two bodies are in contact, the direction of the force of friction on one of them is opposite to the direction in which this body tends to move.
• The frictional force is independent of the area of contact of the surfaces
• When one body is just on the point of sliding over the other body, the maximum force of friction is being exerted; This is called the limiting friction
• The force of friction is dependent upon the types of materials of the two bodies in contact
• The limiting frictional force is proportional to the normal force that acts between the bodies in contact
• The ratio of frictional force to the normal reaction is constant and is known as the coefficient of friction, i.e., μ = F/N
• Limiting static friction is somewhat greater than the kinetic friction
• The kinetic friction is independent of the relative velocity of the bodies in contact

Checking according to given options.

P = hρg

a) ⇒ 10.2 m of fresh water (ρ = 998 kg/m³)

P = 10.2 × 998 × 9.81 = 99861.87 Pa = 99.861 kPa

b) ⇒ 10.1 m of saline water (ρ = 1025 kg/m³)

P = 10.1 × 1025 × 9.81 = 101.558 kPa

c) ⇒ 12.5 m of kerosene of ρ = 800 kg/m³

P = 12.5 × 800 × 9.81 = 98.1 kPa

d) ⇒ 6.4 m of carbon tetrachloride of ρ = 1590 kg/m³

⇒ 6.4 × 1590 × 9.81 = 99.826 kPa

So option b is nearest, so correct

Coefficient of performance of the refrigeration system working on reversed Carnot cycle:

Unit of refrigerating effect = One tonne of refrigeration

1 TR = 3.5 kW

Calculation:

Given: RE = 1 TR = 3.5 kW

W = 700 kJ/ten minutes

COP = 3

Width across flat, W_f = (1.5D + 3 mm)

Width across corners, W_c = 2D

Head thickness, T_h = 0.8 D

Stress-Strain

σ ∝ ϵ

σ = Eϵ

where E is known as Young’s modulus of elasticity.

Since strain (ϵ) is non – dimensional, the unit of E must be the same as those of stress (σ). Thus, E can be expressed in N/mm2, Pa, MPa, GPa, etc.

• Unit of stress: N/mm2 (MPa)

• Unit of strain: Dimensionless

• Unit of Force: N

• Unit of length: mm

As the hot coffee remains hot for a long time so neither heat nor mass is exchanged with the surroundings and hence it is an example of isolated system.

The segment is in passive voice, thus only a verb in third form is eligible for the blank. Among all the given options, only ‘discovered’ fits the blank as the virus already existed in the monkeys but was found in 1970.

Hence, option D is correct.

The sentence "We must respect the elders" in the Active Voice can be transformed into the Passive Voice as:

A. The elders must be respected.

This option accurately conveys the original meaning of the sentence in the Passive Voice.

Pediatrician: A doctor who treats children

Hence option B is correct.

The side of the square must be the same as the breadth of the rectangle.
Side of the square = 4 meters
So the answer = 4 × 4 = 16 m²
Hence, Option D is correct.

Let AB be the kite and AC be the level ground
So that BC - AC.
At that point, ∠BAC = 60°and BC = 75m. Let AB = x meters.
Presently AB/BC = coses60° = 2/ √3
=> x/75 = 2/√3 => x = 150/√3 = 150 * √3/3 = 50 √3m.
∴ Length of the string = 50 √3m.

Base =  7 cm and Height  = 4 cm
Area of  Rhombus = Base×Height
= 7 * 4
= 28 cm²

Circles are all similar, and "the circumference divided by the diameter" produces the same value regardless of their radius. This value is the ratio of the circumference of a circle to its diameter and is called π (Pi). This constant appears in the calculation of the area of a circle and is a type of an irrational number known as a transcendental number that can be expressed neither by a fraction nor by any radical sign such as a square root, nor their combination. 

√4 = 2, √9 = 3, √16 = 4 but √2 = 1.414 it is a non-terminating and non-repeating number and such numbers are called irrational numbers. So, √2 is not a rational number.

As President is the nominal head of a country, similarly Governer is the nominal head of a State.

Ascending order:
686,   719,   765,   795,   815,   822,   835

Middle Number

Middle digit of 795 is 9.

The below figure shown the total no. of triangles is 8 + 8 + 2 + 6 + 4 = 28

Carpenter, Plumber, Electrician and Blacksmith are in same working category.

The logic follows here is:

It is given that Rahul has 48% marks in 10th, an age of 28 years, and work experience of 5 years.

It is clearly mentioned in the criteria that 10^th marks should be greater than 50% for job P and greater than 60% for job Q. Rahul got 48% marks in 10^th.

Therefore, Rahul, neither qualifies for job P nor for job Q.

Hence, the correct answer is "Neither P nor Q".

The correct answer is 'Mandi Gobindgarh'.

Key Points

• Mandi Gobindgarh is a town and municipal committee in Fatehgarh Sahib district in the state of Punjab in North India.
• It is also referred to as the Steel City of Punjab or "Loha Mandi" due to its large number of steel factories.
• The steel melting and re-rolling sector consist of small and medium-scale units.
• The city is also a key industrial center of the state, with plenty of enterprises and industrial companies.
• It is also one of the richest cities in the state.

Additional Information

• Ludhiana
  • ​It is called as Manchester of India.
  • This is due to the reason that it is a major industrial town having a huge number of large and medium scale textile industries (like Vardhman group, Trident group), world-famous hosiery industry, cycle parts industry, and many other types of industrial units.
• Amritsar
  • It is called as Golden City.
  • ​It is named so as Golden Temple, a popular shrine of the Sikh religion is located in the city.
  • The main building is covered with original gold plating, that's why the shrine is known as Golden Temple and the city is called as Golden City.
• Ropar
  • ​Rupnagar formerly known as Ropar is a city and a municipal council in the Rupnagar district in the Indian state of Punjab.
  • Rupnagar is a newly created fifth Divisional Headquarters of Punjab comprising Rupnagar, Mohali, and its adjoining districts.
  • It is also one of the bigger sites belonging to the Indus Valley Civilization.

Important Points

• Manchester is a town in Britain, which got developed as a major hub of industry (mainly the textile industry) during the early days of the industrial revolution in Europe in the early 19th century.
• As it was one of the first industrial towns, so Manchester became an acronym for many major industrial towns in the world.

The correct answer is Breadbasket of India.

Key Points

• Haryana is called the Breadbasket of India.
• A breadbasket is a region of a nation producing large quantities of wheat or other grains due to the richness of the soil and the favorable climate.
• In India, both Punjab and Haryana are referred to as Breadbasket.
  • Haryana accounts for about 9% of India's total wheat production. In the financial year 2019, over 12 million metric tons of wheat were produced in the northern state of Haryana in India. 

Additional Information

About Haryana

• Capital - Chandigarh.
• 1st Chief Minister - Bhagwat Dayal Sharma (Indian National Congress).
• 1st Governor - Dharma Vira.
•  Chief Minister(As of 12 March 2021): Manohar Lal Khattar.
• Governor(July 2021):Bandaru Dattatreya.

correct answer and solution is - ​Religious persecution of the Sikhs by Mughals.

• The rule of the Sikhs over the entire Punjab east of Lahore obstructed the communication between Delhi and Lahore, the capital of Punjab, and this worried Mughal Emperor Bahadur Shah He gave up his plan to subdue rebels in Rajasthan and marched towards Punjab.
• Banda Singh Bahadur is known to have halted the Zamindari and Taluqdari system in the time he was active and gave the farmers proprietorship of their own land.
• It seems that all classes of government officers were addicted to extortion and corruption and the whole system of regulatory and order was subverted.
• Local tradition recalls that the people from the neighborhood of Sadaura came to Banda Singh complaining of the iniquities practices by their landlords.
• Banda Singh ordered Baj Singh to open fire on them.
• The people were astonished at the strange reply to their representation and asked him what he meant.
• He told them that they deserved no better treatment when being thousands in number they still allowed themselves to be cowed down by a handful of Zamindars. He defeated the Sayyids and Shaikhs in the Battle of Sadhaura.