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RRB JE ME (CBT II) Mock Test- 3


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150 Questions MCQ Test RRB JE Mock Test Series for Mechanical Engineering (ME) | RRB JE ME (CBT II) Mock Test- 3

RRB JE ME (CBT II) Mock Test- 3 for Railways 2022 is part of RRB JE Mock Test Series for Mechanical Engineering (ME) preparation. The RRB JE ME (CBT II) Mock Test- 3 questions and answers have been prepared according to the Railways exam syllabus.The RRB JE ME (CBT II) Mock Test- 3 MCQs are made for Railways 2022 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for RRB JE ME (CBT II) Mock Test- 3 below.
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RRB JE ME (CBT II) Mock Test- 3 - Question 1

Identify the heat treatment process which results in a very hard surface even though the core may remain soft and ductile.‌

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 1 Case hardening is a method used to harden the outer surface of low-carbon steel while leaving the centre or core soft and ductile. Case hardening involves heating the metal to its critical temperature in some carbonaceous material. The following methods are commonly used

1. Pack method

2. Cyaniding

3. Nitriding

4. Induction Hardening

5. Flame hardening

Important Points

Heat treatment is an operation involving heating and cooling of a metal or alloy so as to obtain the ,,certain desirable properties. A few important heat treatment processes are:

1. Annealing

2. Normalising

3. Hardening

4. Tempering

RRB JE ME (CBT II) Mock Test- 3 - Question 2

Range of the cannon is 1.5 km when the angle of projection is 15°. What will be the maximum range of the cannon?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 2

Concept:

Time of flight: t =

Maximum height: H =

Horizontal Range: R =

When θ = 45°: Rmax =

The range of a projectile is maximum, when the angle of projection is 45°.

Calculation:

Rmax = R/sin2θ = 15 / sin30o = 3 km

RRB JE ME (CBT II) Mock Test- 3 - Question 3

The coating factor used to make medium coated electrode is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 3 An electrode is a metallic wire of standard size and length, generally coated with flux (may be bare or without flux coating also) used to complete the welding circuit and provide filler material to the joint by an arc, maintained between its tip and the work.

Coating factor: The ratio of the coating diameter to the core wire diameter is called the coating factor.

  • 1.25 to 1.3 for light coated

  • 1.4 to 1.5 for medium coated

  • 1.6 to 2.2 for heavy coated

  • Above 2.2 for super heavy coated electrodes

RRB JE ME (CBT II) Mock Test- 3 - Question 4

In finding Reynold’s number, the characteristic length of circular pipe of diameter d, is taken as

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 4

Reynold Number

Where U is the average stream velocity and L is the characteristics length/width.

The hydraulic diameter which is used as the characteristic length in determination of friction factor, instead of ordinary geometrical diameter, is defined as

where Aw is the flow area and Pw is the wetted perimeter

Circular pipe of diameter d:

Important Points

Square duct of size a:

The rectangular duct of size a × b:

RRB JE ME (CBT II) Mock Test- 3 - Question 5

In the case of PERT, if the most pessimistic, optimistic, and likely time are 10, 2 and 8 days respectively, then the expected duration and variance are

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 5

Concept:

The PERT (Project Evaluation and Review Technique) technique is used, when activity time estimates are stochastic in nature. For each activity, three values of time (optimistic, most likely, pessimistic) are estimated.

  • Optimistic time (to) estimate is the shortest possible time required for the completion of the activity.
  • The most likely time (tm) estimate is the time required for the completion of activity under normal circumstances.
  • Pessimistic time (tp) estimate is the longest possible time required for the completion of the activity.

 

In PERT expected time of an activity is determined by using the below given formula:

Variance, σ2 =

Calculation:

RRB JE ME (CBT II) Mock Test- 3 - Question 6

Food chain in which micro-organisms breakdown the food formed by primary producers is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 6 The dead organic matter of plants or animals is called detritus. While a part of it remains on the soil surface as litter, the other part enters the soil. Many animals such as protozoans, nematodes, insects, etc., depend on detritus, and hence they are called detritivores.

From detritus, the chain proceeds to detritivores, then to carnivores, and finally to top carnivores.

RRB JE ME (CBT II) Mock Test- 3 - Question 7

Many ancient monuments have been spoilt by acid rain, which is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 7 When the quantity of acids in the raining water is more than the average, then such rain is called 'Acid rain'.

We are aware that normally rainwater has a pH of 5.6. When the pH of the rainwater drops below 5.6, it is called acid rain.

Acid rain refers to the ways in which acid from the atmosphere is deposited on the earth’s surface. Oxides of nitrogen and sulphur which are acidic in nature can be blown by the wind along with solid particles in the atmosphere and finally settle down either on the ground as dry deposition or in water, fog and snow as wet deposition.

Acid rain is a byproduct of a variety of human activities that emit the oxides of sulphur and nitrogen in the atmosphere. As mentioned earlier, burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil in power stations and furnaces or petrol and diesel in motor engines produce sulphur dioxide and nitrogen oxides.

SO2 and NO2 after oxidation and reaction with water are major contributors to acid rain because polluted air usually contains particulate matter that catalyses the oxidation.

2SO2 (g) + O2 (g) + 2H2O (l) → 2H2SO4 (aq)

4NO2 (g) + O2 (g)+ 2H2O (l) → 4HNO3 (aq)

The bad effects of acid rain

  • When acid rain falls and flows as groundwater to reach rivers, lakes etc, it affects plants and animal life in the aquatic ecosystem

  • Acid rain is harmful to agriculture, trees,.. and plants as it dissolves and washes away nutrients needed for their growth.

  • It causes respiratory ailments in human beings and animal

  • It may also cause corrosion in many buildings bridges, monuments, fencing etc

  • It causes irritation in the eyes and skin of human beings

  • This rain reduces the lustre of the metals too

  • Acid rain damages buildings and other structures made of stone or metal

  • The Taj Mahal in India has been affected by acid rain

RRB JE ME (CBT II) Mock Test- 3 - Question 8

The prescribed permissible noise level, Leq for commercial area at night-time is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 8 The prescribed permissible noise level for the commercial area is 65 and 55 decibels during daytime and night-time respectively.

Important Points:

  • The prescribed permissible noise level for silence zones is 50 and 40 decibels during daytime and night-time respectively

  • The prescribed permissible noise level for the industrial area is 75 and 70 decibels during daytime and night-time respectively

  • The prescribed permissible noise level for the residential area is 55 and 45 decibels during daytime and night-time respectively

RRB JE ME (CBT II) Mock Test- 3 - Question 9

Which of the following is the only Union Territory to have its own High Court?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 9
  • Delhi is the only union territory of India which has its own High court.

  • It was established on 31 October 1966.

  • The High Court of Delhi was established with Chief Justice KS Hegde, Justice ID Dua, Justice HR Khanna and Justice SK Kapur as the 4 judges.

  • Chandigarh comes under the jurisdiction of Punjab and Haryana High Court.

  • Puducherry comes under the jurisdiction of Madras High Court.

  • Daman and Diu come under the jurisdiction of Bombay High Court.

RRB JE ME (CBT II) Mock Test- 3 - Question 10

Name the deputy Governor of RBI, who resigned in June 2019?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 10
  • With the exit of Viral Acharya, the RBI rejigged portfolios of the other three deputy governors giving the important monetary policy and forecasting department to B P Kanungo.

  • Now, all the other 3 deputy governors -- N S Vishwanathan, B P Kanungo and M K Jain have been made responsible for 12 departments each.

  • Viral Acharya resigned in June 2019 as the deputy Governor of RBI.

RRB JE ME (CBT II) Mock Test- 3 - Question 11

If a body is acted upon by a number of coplanar non-concurrent forces, it may

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 11 If all the forces in a system lie in a single plane and the lines of action of all the forces do not pass through a single point, the system is said to be a coplanar non-concurrent force system.

The Result of a non-concurrent force system is the one which will have the same rotational and translatory effect as the given system of forces. It may be a single force, a pure moment of a force and a moment.

When a body is acted upon by a number of coplanar non-concurrent forces. A little consideration will show, that as a result of these forces, the body may have any one of the following states:

1. The body may move in any one direction.

2. The body may rotate about itself without moving.

3. The body may move in any one direction and at the same time, it may also rotate about itself.

4. The body may be completely at rest.

For Equilibrium of coplanar non-concurrent force system:

ΣFx = 0

ΣFy = 0

ΣM = 0

RRB JE ME (CBT II) Mock Test- 3 - Question 12

The term Municipal Solid Waste is used to describe which kind of solid waste?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 12

Municipal solid waste:

  • Municipal solid waste (MSW) is more commonly known as trash or garbage

  • It consists of everyday items we use and then throw away, such as product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, paint, and batteries.

  • It is the non-hazardous solid waste

  • It comes from our homes, schools, hospitals, and local councils

Important points:

There are different methods of solid waste management. The following are some of the recognized methods:

  • Sanitary landfill

  • Incineration

  • Recovery and Recycling

  • Composting

RRB JE ME (CBT II) Mock Test- 3 - Question 13

The Dead Sea is located between two countries?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 13
  • The Dead Sea is a salt lake which is bordered by Jordan to the east and Israel to the west.

  • The Dead Sea lies in the Jordan Rift Valley, with the Jordan River as its main tributary.

  • Its surface and shores are 430.5 meters (1412 feet) below sea level.

RRB JE ME (CBT II) Mock Test- 3 - Question 14

The radius of curvature of a concave mirror is 30 cm. Following the Cartesian Sign Convention, its focal length is expressed as ________.

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 14 In a concave mirror, the light rays from the object converge after reflection.

Light rays from infinity, parallel to the principal axis, thus meet at the point on the principal axis on the side of the mirror, which is towards the object.

This distance is considered as negative.

Hence the focal length of a concave mirror is negative.

⇒ Focal length, f = R/2

⇒ f = 30/2 = 15 cm

For the Concave mirror, the focal length is negative.

Therefore, f = -15 cm.

RRB JE ME (CBT II) Mock Test- 3 - Question 15

A ball of mass 8 kg is dropped from a height of 20 m. What is the velocity with which it strikes the ground?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 15 PE lost = KE gained

KE gained = mgh

KE gained = 8*10*20

KE gained = 1600 J

KE = (1/2)mv2

1600 = (1/2)*8*v2

Solve for v

V = Square root of 400

V = 20 m/s2

RRB JE ME (CBT II) Mock Test- 3 - Question 16

To an observer on the earth the stars appear to twinkle, this is because:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 16 The twinkling of a star is due to the atmospheric refraction of starlight. The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth.

The atmospheric refraction occurs in a medium of gradually changing refractive index.

Since the atmosphere bends starlight towards the normal, the apparent position of the star is slightly different from its actual position.

RRB JE ME (CBT II) Mock Test- 3 - Question 17

The oxide of an element X is found to be acidic. The element X is:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 17 Metallic Oxides

Most metal oxides are insoluble in water but some of these dissolve in water to form alkalis.

Sodium oxide and potassium oxide dissolve in water to produce alkalis as follows

Na2O(s) + H2O(l) → 2NaOH(aq)

K2O(s) + H2O(l) → 2KOH(aq)

Non-Metallic Oxides:

Most non-metals produce acidic oxides when dissolved in water

CO2 + H2O → H2CO3 (Carbonic acid)

SO­3 + H2O → H2SO4 (Sulphuric acid)

RRB JE ME (CBT II) Mock Test- 3 - Question 18

A forging method for reducing the diameter of a bar and in the process making it longer is termed as

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 18 In fullering: The material cross-section is decreased and length increased. To do this, the bottom fuller is kept in the anvil hole with the heated stock over the fuller. The top fuller is then kept above the stock and then with the sledgehammer, the force is applied on the top fuller. Due to the concentration of force over a very small area, cross-section decreases at that point.

Edging: This applied to increase the cross-sectional area of the stock at the expense of its length.

RRB JE ME (CBT II) Mock Test- 3 - Question 19

Stainless steel contains

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 19

Steel is an alloy of iron and carbon with a carbon content of up to a maximum of 2%.

Stainless steel contains Iron, Carbon, Chromium, and Nickel.

Stainless steels typically contain 10 - 30 % chromium besides other elements like C, Mn, Si, S, etc. Chromium imparts corrosion resistance to steel. Varying amounts of other alloying elements like Ni, Mo, V, Ti, Ni, etc., may be added to obtain certain specific properties.

RRB JE ME (CBT II) Mock Test- 3 - Question 20

A force of 20 N accelerates a body from rest to a velocity of 3 m/s in 10 s. The magnitude of change in momentum of the body in one second is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 20

According to Newton’s Second Law

The rate of change of momentum of an object is directly proportional to the resultant force applied and is in the direction of the resultant force.

Δ(mv) = F × Δt = 20 × 1 = 20 kg m/s

RRB JE ME (CBT II) Mock Test- 3 - Question 21

If a simply – supported beam of span L carries a moment force at its mid-span, then the shear force diagram will be

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 21 If a simply – supported beam of span L carries a moment force at its mid-span, then the shear force diagram will be rectangular, and the bending moment diagram will be triangular.

RRB JE ME (CBT II) Mock Test- 3 - Question 22

The critical path of a network represents

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 22 From the activity network representation, it can be analysed that the minimum time to complete the project is the maximum of all paths from start to finish.

So, the longest path will represent the critical path for the network, and it will represent the minimum possible duration required to complete the project.

The critical path will be the longest path in the network requiring the maximum amount of time, but it will represent the minimum duration that is required to complete all the activities i.e. completion of a project.

RRB JE ME (CBT II) Mock Test- 3 - Question 23

Which of the following is the information retrieval service?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 23
  • The internet is a globally connected network system that transmits data via various types of media. Sometimes it is referred to as a ‘network of networks’

  • The World Wide Web, or simply the web, is a way of accessing information over the medium of the internet.

  • A web browser is a software application for accessing the information on the World Wide Web.

RRB JE ME (CBT II) Mock Test- 3 - Question 24

Strain energy stored in a body of volume V subjected to uniform stress σ is:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 24

When a body is loaded within an elastic limit, it changes its dimensions and on the removal of the load, it regains its original dimensions. So long as it remains loaded, it has stored energy in itself. On removing the load, the energy stored is given off, as in the case of a spring. This energy, which is absorbed in a body when strained within the elastic limit, is known as strain energy.

The strain energy stored in a body due to external loading, within the elastic limit, is known as resilience. The maximum energy stored in a body up to the elastic limit is called proof resilience.

The proof of resilience per unit volume of a material is known as the modulus of resilience.

Strain energy stored in a body due to tensile or compressive load or resilience:

Modulus of resilience:

RRB JE ME (CBT II) Mock Test- 3 - Question 25

Bodies A and B have thermal emissivity of 0.01 and 0.81 respectively. The outer surface areas of the two bodies are the same. The two bodies emit total radiant power at the same rate. Find the temperature of B if the temperature of A is 5802 K.

RRB JE ME (CBT II) Mock Test- 3 - Question 26

Match Material property (List I) with Test to determine material property (List II):

The lista the I (Material property)

List II (Test to determine material property)

A. Ductility

I. Impact Test

B. Endurance limit

II. Fatigue Test

C. Toughness

III. Tension Test

D. Resistance to penetration

IV. Hardness Test

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 26 Impact test signifies toughness, or impact strength, of a material that is the ability of material to absorb energy during plastic deformation.

Ductility is a measure of a material's ability to undergo significant plastic deformation before rupture, which may be expressed as percent elongation or percent area reduction from a tensile test.

In fatigue testing, the endurance limit i.e. the maximum stress which can be applied to a material for an infinite number of stress cycles without resulting in failure of the material is applied and measured.

Hardness is a characteristic of a material, not a fundamental physical property. It is defined as the resistance to indentation, and it is determined by measuring the permanent depth of the indentation. Hardness test is used to determine resistance to penetration.

A. Ductility ⇒ III. Tension Test

B. Endurance limit ⇒ II. Fatigue Test

C. Toughness ⇒ I. Impact Test

D. Resistance to penetration ⇒ IV. Hardness Test

RRB JE ME (CBT II) Mock Test- 3 - Question 27

Where is Kudremukh National Park?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 27
  • Kudremukh National park is located in Chikkamagaluru district of Karnataka.

  • It was declared as a National Park in 1987.

  • Other famous National parks in Karnataka are Bandipur, Nagarhole, and Anshi National Park.

  • Famous National Parks in Kerala are Periyar, Silent Valley, and Anamudi Shola National Park.

  • Famous National Parks in Tamil Nadu are Mudumalai, Mukurthi, and Indira Gandhi National Park.

  • Famous National Parks in Odisha are Simlipal, and Bhitarkanika National park.

RRB JE ME (CBT II) Mock Test- 3 - Question 28

In heat treatment, the sudden cooling of plain carbon steel after attaining the upper critical temperature is to

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 28 The temperature, at which the change of structure to austenite starts, 723°C, is called the lower critical temperature for all plain carbon steels.

The temperature at which the structure of steel completely changes to AUSTENITE is called the upper critical temperature. This varies depending on the percentage of carbon in the steel.

  • 0.57% and 1.15% carbon steel: In these cases, the lower critical temperature is 723°C and the upper critical temperature is 800°C.

  • For 0.84% carbon steel, both lower critical temperature and upper critical temperature are 723°C. This steel is called eutectoid steel.

If steel is heated, a change in its structure commences from 723°C. The new structure formed is called ‘AUSTENITE’. Austenite is non-magnetic.

  • If the hot steel is cooled slowly, the old structure is retained and it will have fine grains which makes it easily machinable.

  • If the hot steel is cooled rapidly the austenite changes into a new structure called ‘MARTENSITE’. This structure is very fine-grained, very hard and magnetic. It is extremely wear-resistant and can cut other metals.

RRB JE ME (CBT II) Mock Test- 3 - Question 29

Why manual stroking is preferred for large quantities in honing operation?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 29 A rotary motion can be given by the spindle and the reciprocating motion can be either manual or by power depending on the type of machine used.

Methods of honing: Manual stroking and Power stroking

Manual stroking

  • Manual stroking is preferred for large quantities when tolerances are extremely close.

  • Many operators prefer this because of the flexibility in operation.

  • This eliminates the use of expensive fixtures to hold the work.

  • Jobs can be quickly changed from one type to another. Jobs can be reversed from end to end for accurate honing and correction.

  • The stroke length can be altered depending on the actual requirement of the individual workpiece.

Power stroking

  • Power stroking is used for honing all types of workpieces. Power stroking may prove to be economical particularly in the case of small parts.

Note

  • Sometimes for final finishing, manual stroking is employed after power stroking.

RRB JE ME (CBT II) Mock Test- 3 - Question 30

The magnification for mechanical comparators vary from

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 30 A comparator does not give the dimension of the workpiece. In comparators, this difference is shown as magnified on the dial or the recording device.

Magnifications of 2000 times are quite common, and some may have as high as 40,000.

If a comparator has a magnification of 1000 and if the difference between the standard and actual dimensions of a work piece is 0.02 mm, it will result in pointer movement of 20 mm on the dial or the recording device of the comparator.

  • In mechanical comparators, the magnification ranges from about 250 to 5000. These comparators are relatively cheap and are used mainly for comparative measurement of external surfaces.

  • With an electrical comparator, magnifications of the order of 40000 or higher are obtainable.

  • With a Pneumatic comparator, the magnification factor will vary from 1000 to 5000.

RRB JE ME (CBT II) Mock Test- 3 - Question 31

Calculate the kinematic viscosity (stoke) of the fluid, if the dynamic viscosity of fluid is 0.5 poise and specific gravity is 0.4?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 31

ν = 1.25 × 10-4 m2/sec

ν = 1.25 cm2/sec

ν = 1.25 stokes

RRB JE ME (CBT II) Mock Test- 3 - Question 32

The term "Stroke" is related to which of the following sports?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 32

SPORTS

TERMS

Swimming

Stroke

Boxing

Jab, Hook, Punch, Knock-out

Chess

Gambit, Checkmate, Stalemate

Billiards

Jigger, Break, Scratch, Cannons

Football

Dribble, Thrown-in, Foul, Touch

Golf

Hole, Bogey, Put, Caddie

RRB JE ME (CBT II) Mock Test- 3 - Question 33

Who took charge as the new Governor of Andhra Pradesh?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 33
  • Biswa Bhusan Harichandan took charge as new Governor of Andhra Pradesh in Rajbhavan in Vijayawada, Andhra Pradesh.

  • His oath was administered by the AP High Court Acting Chief Justice Justice C. Praveen Kumar.

RRB JE ME (CBT II) Mock Test- 3 - Question 34

An operation on lathe where the diameter is increased after operation is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 34

Facing:

  • Facing is an operation of machining the ends of a workpiece to produce a flat surface square with the axis

  • Drilling is the production of cylindrical holes of definite diameters in workpieces by using a multi-point cutting tool called a ‘drill’. It is the first operation done internally for any further operation.
  • A reamer is a multi-point cutting tool used for enlarging by finishing previously drilled holes to accurate sizes.
  • Knurling is the operation of producing a straight lined, diamond-shaped pattern or cross lined pattern on a cylindrical external surface by pressing a tool called a knurling tool. Knurling is not a cutting operation but it is a forming operation. Knurling is done at a slow spindle speed (1/3 the turning speed). However, the the speed & feed given for knurling is divided according to the job material and the finish required.

Purpose of knurling

  • A good grip and make for positive handling
  • Good appearance
  • For raising the diameter to a small range for assembly to get a press fit

RRB JE ME (CBT II) Mock Test- 3 - Question 35

In a tensile test on mild steel specimen, the actual breaking stress as compared to ultimate tensile stress is:-

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 35

  • The maximum load which the specimen can withstand without failure is called the load at the ultimate strength.
  • Beyond point E, the cross-sectional area of the specimen begins to reduce rapidly over a relatively small length of the bar, and the bar is said to form a neck.
  • This necking takes place while the load reduces, and fracture of the bar finally occurs at point F
  • Owing to the large reduction in the area produced by the necking process the actual stress at fracture is often greater than the above value

RRB JE ME (CBT II) Mock Test- 3 - Question 36

A steel rod whose diameter is 2 cm and is 2 m long, experiences heating from 30°C to 150°C. The coefficient of thermal expansion is α = 12 × 10-6/°C and the rod has been restricted in its original position. The thermal stress developed is 288 MPa. What is the value of Young’s modulus (GPa)?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 36

Thermal Stress:

? = ?△TE ⇒ 12 x 10-6 x (150 - 30) x E = 288

E = 0.2 x 106MP? = 200GP?

RRB JE ME (CBT II) Mock Test- 3 - Question 37

The duration of second generation computers is generally accepted

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 37

Generation

Duration

Electronic Component Used

First Generation Computers

1946-1954

Vacuum Tubes

Second Generation Computer

1955-1964

Transistors

Third Generation Computer

1964-1977

Integrated Circuits

Fourth Generation Computer

1978 - Present

VLSI or Microprocessors

Fifth Generation Computer

Present and Future

ULSI or Bio-Chips

RRB JE ME (CBT II) Mock Test- 3 - Question 38

Under whose tenure was Indian National Congress formed?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 38
  • The Indian National Congress was formed under the tenure of Lord Dufferin in 1885.

  • Lord Mayo was responsible for carrying out the census in the Indian History and was the first Governor-General to be murdered in his office.

  • Lord Dalhousie introduced the Doctrine of Lapse, Postal services and Railways in India.

  • Lord Cornwallis introduced the permanent settlement in Bengal and was also known as the Father of Civil services in India.

RRB JE ME (CBT II) Mock Test- 3 - Question 39

For a given level of safety stock and EOQ ordering

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 39 The inventory level at which the order is placed is called the reorder point.

Lead time (L) is the time between placing and receiving an order

Reorder point = daily demand × lead time + safety stock

Important Points

  • Safety stock is the buffer and is defined as the difference between the reorder level and the lead time demand. It is the buffer that we have to make sure that demand that exceeds the lead time demand is met during lead time.
  • The safety stock or buffer stock function concerns short range variation in either demand or replacement. A great deal of inventory planning is devoted to determining the size of safety stocks. Safety stock provides protection against two types of uncertainty with sales in excess of forecast during the replenishment period. The second type of uncertainty concerns delays in replenishment.
  • The reorder point is the inventory level at which a new order is placed. The order must be placed while there is enough stock in place to cover demand during lead time.
  • The inventory level might be depleted at a slower or faster rate during lead time. When demand is uncertain, safety stock is added as a hedge against stock-out

RRB JE ME (CBT II) Mock Test- 3 - Question 40

When a ship floats on water

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 40 According to Archimedes principle when a body is immersed fully or partially in a liquid, it experiences an upward force that is equal to the weight of the fluid displaced by it therefore the mass of water displaced is equal to the mass of the ship
RRB JE ME (CBT II) Mock Test- 3 - Question 41

The operation of finishing a drilled hole to its right size is known as?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 41

Drilling: Operation of making a circular hole by removing a volume of metal from the job by a rotating cutting tool called drill

Boring: Process of enlarging a hole.

Reaming: Operation of finishing a drilled hole.

Counterboring: Operation of boring a second hole, larger in diameter than the first, but concentric with it.

RRB JE ME (CBT II) Mock Test- 3 - Question 42

The electron beam welding can be carried out in:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 42 Electron beam welding joins metals by bombarding a specific confined area of the base metal with high velocity electrons.

The operation is performed in a vacuum to prevent the reduction of electron velocity.

It allows fusion welds of great depth with a minimum width because the beam can be focused and magnified.

RRB JE ME (CBT II) Mock Test- 3 - Question 43

Which one of the following elements is NOT lustrous?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 43 Metals have a natural shine or lustre, unlike non-metals. An exception is Iodine which is non-metals but is inherently lustrous.

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.

Sulphur, a non-metal, is not lustrous.

RRB JE ME (CBT II) Mock Test- 3 - Question 44

Too low welding current in arc welding would result in

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 44 Electrode wire size, welding voltage, current and speed are the four most important welding variables apart from flux.

Welding current is the most influential variable as it controls electrode melting rate, depth of penetration and the amount of base metal fused. However, very high current shall lead to too much penetration resulting in burn through in the metal being joined, excessive reinforcement and increased weld shrinkage and, therefore, a large amount of distortion. On the other hand, low current shall lead to insufficient penetration, lack of fusion and unstable arc.

If the welding speed is increased, power or heat input per unit length of the weld is decreased, less welding material is applied per unit length of the weld, and consequently less weld reinforcement results and penetration decreases. Travel speed is used primarily to control bead size and penetration. It is interdependent with the current.

Excessive high travel speed decreases wetting action, increases the tendency for undercut, arc blow, porosity and uneven bead shapes while slower travel speed reduces the tendency to porosity and slag inclusion.

  • Too low welding current in arc welding would result in excessive piling up of weld metal
  • Too high welding current in arc welding would result in excessive spatter
  • Too fast welding speed in arc welding would result in the too small bead

RRB JE ME (CBT II) Mock Test- 3 - Question 45

What is the cell address of the 4th row and 4th column?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 45
  • Each worksheet is made up of cells and cells are a result of the intersection of rows and columns

  • They are basic units for storing data

  • Each cell gets its name from this intersection

  • The address of a cell that is in column A and has its row number as 4 is referred to as cell A4

  • Thus the letter and number of the intersecting column and row is the cell address

  • A group of contiguous cells is called a range

  • An example of a cell range would be G1: G3

RRB JE ME (CBT II) Mock Test- 3 - Question 46

The rusting of iron is a process where the iron reacts with oxygen to form rust. Chemically the reaction may be written as:

a Fe + b O2 + → c Fe2O3.

In the balanced chemical reaction, the coefficient of Fe ‘a’ is:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 46

Balancing Oxygen:

LHS = 2

RHS = 3

LCM (2,3) = 6

Multiply Oxygen on LHS by 3 and on RHS by 2

a Fe + 3 O2 + → 2 Fe2O3

Balancing Fe:

RHS = 4

LHS = 1

Multiply Fe on LHS by 4

4 Fe + 3 O2 + → 2 Fe2O3

RRB JE ME (CBT II) Mock Test- 3 - Question 47

The method used for taper turning on a lathe machine is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 47 A taper is a gradual increase or decrease in diameter along the length of the job.

The different methods of taper turning on a lathe are:

  • Form tool method

  • Compound slide method

  • Tailstock offset method

  • Taper turning attachment method

RRB JE ME (CBT II) Mock Test- 3 - Question 48

Resistance to localized deformation is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 48

Strength: Measure of the resistance of material to permanent deformation

Ductility: Measure of the degree of plastic deformation

Hardness: Resistance to localized deformation

Creep: Resistance to time dependent deformation under load

Fatigue: Resistance of a material against fluctuating stresses.

Fracture toughness: Resistance to brittle failure

RRB JE ME (CBT II) Mock Test- 3 - Question 49

Which is the correct statement about the law of the polygon of forces?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 49 Laws for the Resultant Force

The resultant force, of a given system of forces, may also be found out by the following laws:

1. Triangle law of forces.

2. Polygon law of forces.

Triangle Law of Forces

It states, “If two forces acting simultaneously on a particle, are represented in magnitude and direction by the two sides of a triangle, taken in order; their resultant may be represented in magnitude and direction by the third side of the triangle, taken in the opposite order.”

Polygon Law of Forces

It is an extension of Triangle Law of Forces for more than two forces, which states, “If a number of forces acting simultaneously on a particle, be represented in magnitude and direction, by the sides of a polygon taken in order; then the resultant of all these forces may be represented, in magnitude and direction, by the closing side of the polygon, taken in the opposite order.”

RRB JE ME (CBT II) Mock Test- 3 - Question 50

Which of the following processes will be preferred for joining thin foils?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 50
  • Friction Welding: In this process, the heat for welding is obtained from mechanically induced sliding motion between rubbing surfaces of workpieces. Friction welded parts are used as a product for aerospace, agriculture, automotive, defense, marine and oil industries.

  • TIG welding (Gas Tungsten Arc Welding) is used for welding ferrous metals, stainless steel, aluminum and thin sheet metal welding.

  • Plasma Arc welding is also used to join thin sheet metals.

  • Laser Welding is a method in which a work piece is melted and joined by a narrow beam of intense Monochromatic Light. (Laser Beam) When the beam strikes the job, the heat produced melts and fuses even the hardest materials. Laser Welding is used in the Space, Aircraft, Electronics industries for thinner section metals and dissimilar metals.

  • Thermit welding is used for joining thick, heavy, irregularly shaped rods, like rails, etc. using a chemical heating process.

RRB JE ME (CBT II) Mock Test- 3 - Question 51

Pseudo plastic is a fluid for which

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 51

RRB JE ME (CBT II) Mock Test- 3 - Question 52

The pressure inside a soap bubble of 50 mm diameter is 25 N/m² above the atmospheric pressure. The surface tension in soap film would be

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 52

Pressure intensity inside a soap bubble,

p = 4? /r

? = pr/4 = 25 x 25 x 10

= 0.15625 N/m

RRB JE ME (CBT II) Mock Test- 3 - Question 53

A mercury-water manometer has a gauge difference of 500 mm (difference in elevation of menisci.) What will be the difference in pressure?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 53

Difference in pressure

= x 0.5

= 6.3 m

RRB JE ME (CBT II) Mock Test- 3 - Question 54

The centre of pressure for an inclined surface area

RRB JE ME (CBT II) Mock Test- 3 - Question 55

A bucket of water hangs with a spring balance. If an iron piece is suspended into water from another support without touching the sides of the bucket, the spring balance will show

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 55 Since the water of the bucket will exert the A surge,the force of buoyancy equal to the volume displaced by the iron block. Hence equal and opposite force will be exerted by iron block on water hence the reading of the spring balance will increase.
RRB JE ME (CBT II) Mock Test- 3 - Question 56

One kg of diatomic Oxygen is present in a 500 L tank. Find the specific volume on both mass and mole basis.

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 56

The specific volume on mass basis= 0.5/1 = 0.5 m3/kg

specific volume on mole basis= 0.5/(1/0.032) = 0.0160 m3/mole.

RRB JE ME (CBT II) Mock Test- 3 - Question 57

For an irrotational motion

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 57 For irrotational motion, the circulation around any path is zero because circulation is the product of vorticity and area. Vorticity is twice of rotation. Hence for an irrotational motion, vorticity is zero and hence circulation is zero.
RRB JE ME (CBT II) Mock Test- 3 - Question 58

Match List-I (Measuring device) with List-II (Parameters) regarding a body partly submerged in a liquid and select the correct answer using the codes given below the lists:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 58

Anemometer: It is a device for measuring wind speed, and it is a common weather station instrument.

Orifice plate: It is a device used for measuring the volumetric flow. It uses Bernoulli's principle.

RRB JE ME (CBT II) Mock Test- 3 - Question 59

Why are surge tanks used in pipelines?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 59 Surge tank is an open reservoir provided in between penstock to

(i) absorb the pressure wave due to sudden blockage of flow in the turbine which will reduce water pressured hammer problem

(ii) to serve for emergency supply and to maintain constant head at inlet of the turbine

RRB JE ME (CBT II) Mock Test- 3 - Question 60

Air is flowing over a flat plate with a free steam velocity of 24 m/s, and its kinematic viscosity is 72 If a particular point, the Reynolds number is 30000, its location from the leading edge is.

RRB JE ME (CBT II) Mock Test- 3 - Question 61

The Reynolds number of a fluid flowing over a flat plate at a distance of 16 cm from the leading edge is 25600. The thickness of the boundary layer at this point will be

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 61

RRB JE ME (CBT II) Mock Test- 3 - Question 62

The friction factor for fully developed turbulent flow through a rough circular pipe depends on

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 62 In fully turbulent flow through pipes the friction factor is independent of the Reynold number only when the number is very high, otherwise a turbulent flow friction factor depends on both roughness and Reynold number. Therefore correct option (c).
RRB JE ME (CBT II) Mock Test- 3 - Question 63

A piston/cylinder with a cross-sectional area of 0.01 m^2 is resting on the stops. With an outside pressure of 100 kPa, what should be the water pressure to lift the piston?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 63 Pw = Po + mg/A = 100000 + (100*9.8/0.01) = 198kPa.
RRB JE ME (CBT II) Mock Test- 3 - Question 64

Priming is necessary for

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 64 filling the pump casing and the suction pipe with the liquid before it is started is known as priming. Unless the centrifugal pump is primed, it will not start as there is no centrifugal head impressed on the liquid. Positive displacement type reciprocating or rotary pumps do not need priming because the air, if any, in the cylinder or casing is driven out by the piston or vanes.
RRB JE ME (CBT II) Mock Test- 3 - Question 65

Why is an air vessel used in a reciprocating pump?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 65 Air vessel are fitted to the delivery side of the reciprocating pump due to the following reason

(a) constant rate of discharge can be ensured

(b) power consumption can be reduced because it reduces friction losses.

RRB JE ME (CBT II) Mock Test- 3 - Question 66

A large exhaust fan in a lab room keeps the pressure inside at 10 cm water relative to the vacuum of the hallway? What is the net force acting on the door measuring 1.9 m by 1.1 m?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 66 Net force acting on the door = Gauge pressure*area

= 0.1cm water*1.9*1.1 = 2050 N.

RRB JE ME (CBT II) Mock Test- 3 - Question 67

The value of compressibility factor for an ideal gas may be:

1. Less or more than one

2. Equal to one

3. Zero

4. Less than zero

The correct value (s) is/are given by

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 67 For real gases, Z can be greater than or less than unity. The farther Z is away from unity the more the gas deviates from ideal gas behavior.
RRB JE ME (CBT II) Mock Test- 3 - Question 68

A 5 m long vertical tube having cross sectional area 200 cm^2 is placed in water. It is filled with 15°C water, with the bottom closed and the top open to 100 kPa atmosphere. How much water is present in the tube?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 68 m = ρ V = V/v = AH/v

= 200 × 10^(−4) × 5/0.001001 = 99.9 kg.

RRB JE ME (CBT II) Mock Test- 3 - Question 69

Match List-I (Process index ‘n’) with List-II (T-s traces) and select the correct answer using the code given below the lists

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 69

RRB JE ME (CBT II) Mock Test- 3 - Question 70

Match List-I with List-II and select the correct answer using the codes given below the lists:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 70

A. Work done in a polytropic process :

B. Work done in a steady flow process : ∫C dp

C. heat transfer in a reversible adiabatic process : zero

D. Work done is an isentropic process:

RRB JE ME (CBT II) Mock Test- 3 - Question 71

A tank containing air is stirred by a paddle wheel. The work input to the paddle wheel is 9000 kJ and the heat transferred to the surrounding from the tank is 3000 kJ. The external work done by the system is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 71

This is a case of a constant volume process or an isochoric process. In an irreversible constant volume process, the system doesn’t perform work on the surrounding at the expense of its normal energy. By performing work on the system, the temperature can be raised.

RRB JE ME (CBT II) Mock Test- 3 - Question 72

An ideal air standard cycle is shown in the given temperature-entropy diagram

The same cycle, when represented on the pressure-volume coordinates, takes the form.

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 72

In T - S diagram

Process 1 - 2 → Isothermal process

Process 3 -1 → reversible adiabatic process

Thus, on the P-V diagram, the slope of the reversible adiabatic process

(3-1) is more than the slope of the isothermal process (1 - 2).

Process 2 - 3 → isobaric process line

RRB JE ME (CBT II) Mock Test- 3 - Question 73

In a heat engine operating in a cycle between a source temperature of 606°C and a sink temperature of 20°C, what will be the least rate of heat rejection per kW net output of the engine?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 73

T1 = 606 + 273 = 879 K

T2 = 20 + 273 = 293 K

n = T1 - T,/T1

= 879 - 293 / 879 = W/Q1 (since W = 1 kW)

0.666 = 1/Q1

Q1 = 1.5 kW

Amount of heat rejected

Q2 = Q1 - W = 1.5 - 1.0 = 0.5 kW

RRB JE ME (CBT II) Mock Test- 3 - Question 74

The value of for an irreversible cycle is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 74

From Clausius inequality

for reversible cycle

for irreversible cycle

RRB JE ME (CBT II) Mock Test- 3 - Question 75

A 5 m long vertical tube having cross sectional area 200 cm2 is placed in water. It is filled with 15°C water, with the bottom closed and the top open to 100 kPa atmosphere. What is the pressure at the bottom of the tube ?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 75

∆P = ρ gH = gH/v = 9.80665 × 5/0.001001

= 48.98 kPa

P(total) = P(top) + ∆P = 149 kPa.

RRB JE ME (CBT II) Mock Test- 3 - Question 76

Consider the following thermodynamic relation

1. Tds = du + pdV

2. Tds = du – pdV

3. Tds = dh + Vdp

4. Tds = dh - Vdp

Which of these thermodynamic relations are correct?

RRB JE ME (CBT II) Mock Test- 3 - Question 77

Find the pressure of water at 200°C and have a specific volume of 1.5 m3/kg.

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 77 The state is superheated vapour between 100 and 150 kPa.

v = 1.3136 + (0.8689 – 1.3136)(140 − 100)/(150 – 100)

= 1.3136 + ( − 0.4447) × 0.8 = 0.9578 m3/kg.

RRB JE ME (CBT II) Mock Test- 3 - Question 78

The device used to heat feed-water by utilizing the heat of the exhaust flue gases before leaving through the chimney, is called

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 78 Economiser is situated before air pre-heater in the flue gas path.
RRB JE ME (CBT II) Mock Test- 3 - Question 79

Find the pressure of water at 200°C and have a specific volume of 1.5 m3/kg.

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 79 v > vg so that it is superheated vapour.

Between 100 kPa and 200 kPa,

P = 100 + (200 – 100)(1.5 − 2.17226)/(1.08034 − 2.17226)

= 161.6 kPa.

RRB JE ME (CBT II) Mock Test- 3 - Question 80

In a centrifugal compressor, an increase in speed at a given pressure ratio causes.

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 80 By increase in speed at a given pressure ratio, mass flow rate increases but-efficiency decreases due to various frictional losses.
RRB JE ME (CBT II) Mock Test- 3 - Question 81

Consider the following features for a gas turbine plant:

1. Intercooling

2. Regeneration

3. Reheat

Which of the above features in a simple gas turbine cycle increases the work ratio?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 81

Work ratio = net work / positive work = WT - WC / WT

RRB JE ME (CBT II) Mock Test- 3 - Question 82

The propulsive efficiency of a turbo-jet aircraft approaches 100% when the thrust approaches

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 82

Propulsive efficiency is maximum when jet velocity (Cj) = forward velocity of aircraft (Ca)

Now thrust power = (Cj - Ca)Ca = 0

I.e. at maximum efficiency thrust power is zero.

RRB JE ME (CBT II) Mock Test- 3 - Question 83

A refrigerating machine working on a reversed Carnot cycle takes out 2 kW per minute of heat from the system while between temperature limits of 300 K and 200 K. COP and power consumed by the cycle will be respectively.

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 83

RRB JE ME (CBT II) Mock Test- 3 - Question 84

Match list I with list II and select the correct answer using the codes given below the lists:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 84

1. Bell Coleman refrigeration: Expansion cylinder

2. Vapour compression refrigeration: compressor

3. Absorption refrigeration: Generator

4. Jet Refrigeration: Flash chamber

RRB JE ME (CBT II) Mock Test- 3 - Question 85

What is an azeotrope?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 85 Azeotrope is a mixture of refrigerants without phase separation.
RRB JE ME (CBT II) Mock Test- 3 - Question 86

Air at 35°C DBT and 25°C dew point temperature passes through the water shower whose temperature is maintained at 20°C. What is the process involved?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 86 As the temperature of the water shower is less than dew point temperature hence, water vapour starts condensing. Thus, the process involved is cooling and dehumidification.
RRB JE ME (CBT II) Mock Test- 3 - Question 87

For an air-conditioned space, RTH = 100 kW, RSHF = 0.75, volume flow rate = 100 m³/min, and indoor design specific humidity is 0.01 kg/kg of dry air. What is the specific humidity of the supply air?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 87

RSHF = RSH / RTH

RSH = 0.75 x 100 = 75 kW

RLH = 100 - 75 = 25 kW

RLH = 50 cmm (w1 -w2)

W2 = 0.005kg/kg of dry air

RRB JE ME (CBT II) Mock Test- 3 - Question 88

In an air-standard Diesel cycle; r is the compression ratio, ρ is the fuel cut-off ratio and γ is the adiabatic index . Its air standard efficiency is given by

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 88

n of diesel engine increases as the load on the engine decreases and at a limiting condition becomes Otto. With increase in load, the cut off ratio increases.

RRB JE ME (CBT II) Mock Test- 3 - Question 89

A Carnot engine receives 100 kJ of heat at 600 K. Heat is rejected at 300 K. The displacement volume is 0.2 m³. The mean effective pressure is

RRB JE ME (CBT II) Mock Test- 3 - Question 90

Piston compression rings are made of which one of the following?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 90 Since grey cast iron has properties of self lubrication and damping of small vibrations they are widely used for machine base, engine frames, drainage pipes, elevator and industrial furnace counter weights, pump housings cylinder and piston rings of IC engines, flywheel etc.
RRB JE ME (CBT II) Mock Test- 3 - Question 91

The knocking tendency in compression ignition engines increases with

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 91 Decrease of compression ratio will reduce temperature and increase delay period. This increases the knocking tendency in CI engines.
RRB JE ME (CBT II) Mock Test- 3 - Question 92

The centre number of automotive diesel fuel used in India is in which one of the following ranges?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 92 In India, the the tane number lies between 40 to 60.
RRB JE ME (CBT II) Mock Test- 3 - Question 93

A copper block and an air mass block having similar dimensions are subjected to symmetrical heat transfer from one face of each block. The other face of the block will be reaching to the same temperature at a rate

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 93 Thermal conductivity of copper is around 380 W/mK and air is around 0.026 W/mK. Since thermal conductivity of copper is higher than air, hence heat flow will be faster in copper blocks.
RRB JE ME (CBT II) Mock Test- 3 - Question 94

A hollow pipe of 1 cm outer diameter is to be insulated by thick cylindrical insulation having thermal conductivity 1 W/mK. The surface heat transfer coefficient on the insulation surface is 5 W/m²K. What is the minimum effective thickness of insulation for causing the reduction in heat leakage from the insulated pipe?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 94

rc = k/h = ⅕ = 20 cm

Thickness = 20 cm - 0.5 cm = 19.5 cm

RRB JE ME (CBT II) Mock Test- 3 - Question 95

Dimensionless time is represented by

RRB JE ME (CBT II) Mock Test- 3 - Question 96

The effectiveness of a fin will be maximum in an environment with

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 96 The effectiveness of fin will be maximum in an environment where h is minimum.
RRB JE ME (CBT II) Mock Test- 3 - Question 97

For a fluid flowing over a flat plate, the Nusselt number at a point 0.5 m from the leading edge is 100. If the thermal conductivity of the fluid is 0.025 W/mK, the coefficient of convective heat transfer is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 97

Nusselt number = hL/k

100= h x 0.5/0.025

h = 5 W / M2K

RRB JE ME (CBT II) Mock Test- 3 - Question 98

Match List-I with List-II and select the correct answer using the codes given below the lists:

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 98 Radiosity is the rate at which energy is leaving from the surface (reflection and emission both). Gray surface is an imaginary surface which have emissivity independent of wavelength.
RRB JE ME (CBT II) Mock Test- 3 - Question 99

In a counter flow heat exchanger, the product of specific heat and mass flow rate is the same for the hot and cold fluids. If NTU is equal to 0.5 then the effectiveness of the heat exchanger is

RRB JE ME (CBT II) Mock Test- 3 - Question 100

Which of the following elements were not found in the form of archaeological remains from Kalibangan?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 100 Kalibangan in Rajasthan has given the evidence of the earliest (c. 2800 BC) ploughed agricultural field. At Kalibangan, fire altars have been discovered. Black Copper bangles are also found at Kalibangan. Couple burials are absent in Kalibangan.
RRB JE ME (CBT II) Mock Test- 3 - Question 101

According to Lami’s theorem

RRB JE ME (CBT II) Mock Test- 3 - Question 102

Two coplanar couples having equal and opposite moments

RRB JE ME (CBT II) Mock Test- 3 - Question 103

A framed structure is perfect if it contains members equal to When, n = number of joints in a frame

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 103 Compound trusses are statically determinate, rigid, and completely constrained.

m = 2n – 3

Truss contains a redundant member and is statically indeterminate

m > 2n - 3

RRB JE ME (CBT II) Mock Test- 3 - Question 104

At what height from the base of a pillar must the end of a rope of given length (l) be fixed so that a man standing on the ground and pulling it at the other end with given force may have the greatest tendency to make the pillar overturn

RRB JE ME (CBT II) Mock Test- 3 - Question 105

Which is the false statement about the true stress-strain method?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 105 Stress–strain analysis (or stress analysis) is an engineering discipline that uses many methods to determine the stresses and strains in materials and structures subjected to forces.
RRB JE ME (CBT II) Mock Test- 3 - Question 106

In a tensile test on mild steel specimen, the breaking stress as compared to ultimate tensile stress is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 106 Ultimate stress is the maximum value of stress. It is the point at which the size (cross section area) decreases and a neck is formed, and breaking stress is the stress at which the material actually breaks down.

The value of ultimate stress is always more than the breaking stress as formation of the neck (permanent deformation) requires more stress than to actually break.

RRB JE ME (CBT II) Mock Test- 3 - Question 107

If a part is constrained to move and heated, it will develop

RRB JE ME (CBT II) Mock Test- 3 - Question 108

Which of the following materials is most elastic?

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 108 ‘Mild Steel’ is more elastic than ‘Rubber’.
RRB JE ME (CBT II) Mock Test- 3 - Question 109

The value of Poisson’s ratio for steel is between

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 109

μ = 0 to 0.5 (under uniaxial loading)

μ = 0 for cork

μ = 0.5 for perfectly plastic body (Rubber)

μ = .25 to 0.33 for steel

RRB JE ME (CBT II) Mock Test- 3 - Question 110

The buckling load for a given material depends on

RRB JE ME (CBT II) Mock Test- 3 - Question 111

Relationship between the number of links ( L) and the number of pairs (P) is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 111 Relation between the number of links and number of pair

L = 2P – 4

Where, L = Number of links

P = Number of Pair

RRB JE ME (CBT II) Mock Test- 3 - Question 112

The criterion of the constraint of a chain as enunciated by A.W. Klein, connecting the number of binary joints ( J), number of higher pairs ( H), and number of links ( L), is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 112

Relation between number of binary joints and number of links

2J = 3I -4

Where, J = Number of binary joint

L = Number of link

(i) If LHS > RHS – Locked Chain or frame or structure

(ii) If LHS = RHS – Kinematic Chain or Constrained Chain

(iii) If LHS < RHS – Unconstrained Chain

RRB JE ME (CBT II) Mock Test- 3 - Question 113

In Problem 62, the chain is locked when

RRB JE ME (CBT II) Mock Test- 3 - Question 114

With single Hooke’s joint it is possible to connect two shafts, the axes of which have an angular misalignment upto

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 114

The Hooke’s joint or coupling is connected to two members A&B. ‘A’ is a static rod that rotates the ‘B’ rod. The ‘A’ rod rotation allows the rod to 'bend' in any direction and is commonly used in shafts that transmit ‘rotary motion’.

RRB JE ME (CBT II) Mock Test- 3 - Question 115

The Hooke’s joint consists of:

RRB JE ME (CBT II) Mock Test- 3 - Question 116

The Klein’s method of construction for reciprocating engine mechanism

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 116 In Klein’s Construction, the velocity and the acceleration diagrams are made on the configuration diagram itself. The line that represents the crank in the configuration diagram also represents the velocity and acceleration of its moving end in the velocity and acceleration diagram.
RRB JE ME (CBT II) Mock Test- 3 - Question 117

It is required to connect two parallel shafts, the distance between whose axes is small and variable. The shafts are coupled by

RRB JE ME (CBT II) Mock Test- 3 - Question 118

The c.g. of a link in any mechanism would experience

RRB JE ME (CBT II) Mock Test- 3 - Question 119

The maximum speed of the flywheel is 1000 rpm. The coefficient of steadiness for the flywheel is 50. The maximum variation of speed for the flywheel is

RRB JE ME (CBT II) Mock Test- 3 - Question 120

The shear modulus of resilience of a material is proportional to

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 120

RRB JE ME (CBT II) Mock Test- 3 - Question 121

If a load W is applied instantaneously on a bar; then the stress induced in the bar will

RRB JE ME (CBT II) Mock Test- 3 - Question 122

If a prismatic bar having an elliptical hole in centre with semi-major axis b perpendicular to direction of loading and semi-minor axis c along the direction of loading is subjected to pull F, then the maximum stress induced at edge of the hole will be

Where, s= stress for a uniform bar having no hole.

RRB JE ME (CBT II) Mock Test- 3 - Question 123

Brittle coating technique is used for

RRB JE ME (CBT II) Mock Test- 3 - Question 124

Stress concentration is caused due to

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 124 Stress concentration is the localized stress considerably higher than average, even in a uniformly loaded cross-section of uniform thickness due to abrupt change in the geometry or localised loading. The stress concentration factor is not considered harmful for ductile materials in static loading because of local yielding in ductile materials when relieving the stress concentration. When the stress in the vicinity of the discontinuity reaches the yield point, plastic deformation results in the redistribution of stresses. This plastic deformation prevents the harmful effects of stress concentration in ductile materials.

While in Brittle materials, stress concentration factor is important in both static and dynamic loading. Brittle materials fail due to fracture. So there is little deformation to relax the concentrated stresses and thus has damaging effects.

RRB JE ME (CBT II) Mock Test- 3 - Question 125

Welding process in which two pieces to be joined are overlapped and placed between two electrodes is known as

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 125 In resistance spot welding, two or more sheets of metal are held between electrodes through which welding current is supplied for a definite time and also force is exerted on work pieces.

RRB JE ME (CBT II) Mock Test- 3 - Question 126

Half corner weld is used

RRB JE ME (CBT II) Mock Test- 3 - Question 127

In resistance welding, voltage used for heating is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 127 Resistance welding processes are pressure welding processes in which heavy current is passed for a short time through the area of interface of metals to be joined. These processes differ from other welding processes in the respect that no fluxes are used, and filler metal rarely used. All resistance welding operations are automatic and, therefore, all process variables are preset and maintained constant. Heat is generated in a localized area which is enough to heat the metal to sufficient temperature, so that the parts can be joined with the application of pressure. Pressure is applied through the electrodes.

The process employs currents of the order of few KA, voltages range from 2 to 12 volts and times vary from few milliseconds to few seconds.

RRB JE ME (CBT II) Mock Test- 3 - Question 128

Best reason to decide the use of welding in preference to riveting for structural work on an extension to a hospital could be

RRB JE ME (CBT II) Mock Test- 3 - Question 129

In resistance welding, the pressure is released

RRB JE ME (CBT II) Mock Test- 3 - Question 130

Grey cast iron is best welded by

RRB JE ME (CBT II) Mock Test- 3 - Question 131

Seam welding is

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 131 In seam welding, overlapping sheets are gripped between two wheels or roller disc electrodes, and current is passed to obtain either the continuous seam i.e., overlapping weld nuggets, or intermittent seam, i.e., weld nuggets are equally spaced. Welding current may be continuous or in pulses.
RRB JE ME (CBT II) Mock Test- 3 - Question 132

Upto what thickness of plate, edge preparation for welding is not required

RRB JE ME (CBT II) Mock Test- 3 - Question 133

Loam sand comprises of

RRB JE ME (CBT II) Mock Test- 3 - Question 134

Dilatometer is used to find out following property of moulding sand

RRB JE ME (CBT II) Mock Test- 3 - Question 135

The purpose of sprue is to

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 135 The metal flows down from the pouring basin or pouring cup into the down gate or sprue and passes through the cross gate or channels and ingates or gates before entering into the mold cavity.

To avoid aspiration, the tapered sprues are designed in the gating systems. A sprue tapered to a smaller size at its bottom will create a choke which will help keep the sprue full of molten metal.

RRB JE ME (CBT II) Mock Test- 3 - Question 136

The mould for casting ferrous materials in the continuous casting process is made of

RRB JE ME (CBT II) Mock Test- 3 - Question 137

Sand slinger gives

RRB JE ME (CBT II) Mock Test- 3 - Question 138

The trowel in a foundry shop is used to

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 138 Trowel is a tool, which is used for basically repairing the mold, it has basically a wooden handle and a steel blade or iron blade, and it is used for taking the sand, and filling somewhere, repairing. So, all this work is done using a trowel.
RRB JE ME (CBT II) Mock Test- 3 - Question 139

When using disposable patterns, should the metal be poured?

RRB JE ME (CBT II) Mock Test- 3 - Question 140

If V is the volume of metal in a casting and A its surface area, then the time of solidification will proportional to

RRB JE ME (CBT II) Mock Test- 3 - Question 141

In compression, a prism of brittle material will break

RRB JE ME (CBT II) Mock Test- 3 - Question 142

The ability of a material to resist softening at high temperature is known as

Detailed Solution for RRB JE ME (CBT II) Mock Test- 3 - Question 142 Heat treatments are carried out to change the properties of materials by changing the microstructure of materials. The primary aim of the majority of heat treatments is to change the mechanical properties of the given material; primarily, they are used either to harden (precipitation hardening, quenching, carburising, nitriding, etc) or soften (tempering, annealing, stress relieving, etc.). Hence, in most cases, the success or failure of heat treatment is decided by the mechanical property measurements; more specifically, hardness is the typical quantity measured. Hence, in this module, we discuss some of the standard hardness measurements briefly.
RRB JE ME (CBT II) Mock Test- 3 - Question 143

Mild steel belongs to the following category

RRB JE ME (CBT II) Mock Test- 3 - Question 144

The ultimate tensile strength of low carbon steel by working at a high strain rate will

RRB JE ME (CBT II) Mock Test- 3 - Question 145

For a product layout, the material handling equipment must

RRB JE ME (CBT II) Mock Test- 3 - Question 146

Travel charts provide

RRB JE ME (CBT II) Mock Test- 3 - Question 147

Product layout is employed for

RRB JE ME (CBT II) Mock Test- 3 - Question 148

The most important objective behind plant layout is

RRB JE ME (CBT II) Mock Test- 3 - Question 149

The process layout is best suited where

RRB JE ME (CBT II) Mock Test- 3 - Question 150

A heavy ladder resting on the floor and against a vertical wall may not be in equilibrium, if

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