WILEY ACING THE GATE MECHANICAL ENGINEERING

CONTENTS
Preface v
About GATE xi
Syllabus of GATE (Mechanical Engineering) xiii
Strategy for Success in GATE xv
Methodological Concepts of Engineering Studies xvii
PART I APPLIED MECHANICS & DESIGN 1
1 Engineering Mechanics 3
1.1 Force 3
1.1.1 Characteristics of a Force 3
1.1.2 Resolutions of a Force 4
1.2 Moment of a Force 4
1.2.1 Definition 4
1.2.2 Resultant Moment of a System of Forces 4
1.2.3 Varignon’s Theorem 5
1.2.4 Principle of Moments 5
1.2.5 Moment of a Couple 5
1.3 Equivalent System of a Force 5
1.4 Single Resultant Force 6
1.5 Equilibrium of Rigid Bodies 6
1.5.1 General Condition 6
xx CONTENTS
1.5.2 Free Body Diagrams 7
1.5.3 Support Reactions 7
1.5.4 Equilibrium of Three Coplanar Forces 8
1.5.5 Triangle Law of Forces 8
1.5.6 Lami’s Theorem 8
1.6 Structural Analysis 9
1.6.1 Trusses and Frames 9
1.6.2 Assumptions 9
1.6.3 Method of Joints 9
1.6.4 Zero-Force Members 9
1.6.5 Method of Sections 10
1.7 Rectilinear Kinematics 10
1.8 Angular Motion 11
1.9 Motion Under Gravity 11
1.9.1 Universal Gravitation 11
1.9.2 Earth’s Gravity 11
1.9.3 Projectile 12
1.9.4 Vertical Projection 12
1.10 Dependent Motion of Particles 12
1.11 Newton’s Laws of Motion 12
1.12 Work and Energy 13
1.12.1 Energy 13
1.12.2 Modes of Mechanical Energy 13
1.12.3 Principle of Work and Energy 14
1.12.4 Principle of Conservation of Energy 14
1.13 D’Alembert’s Principle 14
1.14 Impulse and Momentum 14
1.14.1 Linear Momentum 14
1.14.2 Angular Momentum 14
1.14.3 Impulse–Momentum Principle 15
1.15 Law of Restitution 15
1.16 Principle of Virtual Work 16
Important Formulas 17
Solved Examples 18
GATE Previous Years’ Questions 22
Multiple Choice Questions 31
Numerical Answer Questions 39
Answers 41
Explanations and Hints 41
2 Strength of Materials 51
2.1 Stress and Strain 51
2.1.1 Types of Stresses 51
2.1.2 Types of Strains 52
2.1.3 Saint Venant’s Principle 52
2.1.4 Hooke’s Law 53
2.1.5 Bar of Uniform Strength 54
CONTENTS xxi
2.1.6 True Stress and True Strain 54
2.1.7 Poisson Ratio 55
2.1.8 Elastic Constants 56
2.1.9 Principle of Superposition 57
2.1.10 Thermal Loads 57
2.2 Dynamic Loading 58
2.2.1 Impact Load 58
2.2.2 Shock Load 59
2.3 Bi-Axial Stress and Strain 59
2.3.1 Plane Stress 59
2.3.2 Plane Strain 60
2.4 Mohr’s Circle 60
2.4.1 Mohr’s Circle for Plane Stress 61
2.4.2 Mohr’s Circle for Plane Strain 62
2.5 Beam Loading 62
2.5.1 Types of Beams 62
2.5.2 Transverse Loads 62
2.5.3 Support Reactions 63
2.5.4 SF and BM Diagrams 64
2.6 Theory of Bending 65
2.6.1 Bending Stresses 65
2.6.2 Shear Stresses 66
2.6.3 Area Moment of Inertia 67
2.6.4 Expressions for Shear Stress 69
2.7 Beam Deflection 71
2.7.1 Double Integration Method 71
2.7.2 Macaulay’s Method 72
2.7.3 Moment-Area Method 72
2.7.4 Strain Energy Method 74
2.8 Torsion in Shafts 75
2.8.1 Shear Stresses 75
2.8.2 Torsional Strain Energy 76
2.8.3 Composite Shafts 77
2.8.4 Thin-Walled Tubes 77
2.8.5 Helical Springs 77
2.9 Combined Stresses 79
2.10 Thick-Walled Shells 80
2.10.1 Thick-Walled Cylinders 80
2.10.2 Compound Cylinders 82
2.10.3 Thick-Walled Spheres 83
2.11 Thin-walled Shells 85
2.11.1 Thin-Walled Cylinder 85
2.11.2 Thin-Walled Spheres 86
2.12 Struts and Columns 86
2.12.1 Axial Loading 86
2.12.2 Eccentric Loading 88
Important Formulas 90
xxii CONTENTS
Solved Examples 92
GATE Previous Years’ Questions 97
Multiple Choice Questions 116
Numerical Answer Questions 125
Answers 127
Explanations and Hints 127
3 Theory of Machines 145
3.1 Mechanisms and Machines 145
3.1.1 Rigid and Resistant Bodies 145
3.1.2 Kinematic Links 145
3.1.3 Kinematic Pairs 146
3.1.4 Kinematic Chains 147
3.1.5 Inversions of Kinematic Chain 147
3.1.6 Four-Bar Chains 147
3.1.7 Slider Crank Mechanism 148
3.1.8 Double Slider Crank Mechanism 149
3.1.9 Degrees of Freedom 150
3.2 Universal Joint 151
3.2.1 Shaft Rotations 151
3.2.2 Shaft Speeds 151
3.2.3 Angular Acceleration 152
3.2.4 Double Hooke’s Joints 152
3.3 Kinematic Analysis 152
3.3.1 Velocity of a Link 153
3.3.2 Acceleration in Mechanism 154
3.4 Cam Follower Mechanism 156
3.4.1 Types of Cams 156
3.4.2 Types of Followers 156
3.4.3 Terminology 156
3.4.4 Motion of the Follower 157
3.5 Gears 160
3.5.1 Classification 160
3.5.2 Gear Terminology 161
3.5.3 Law of Gearing 162
3.5.4 Teeth Profiles 163
3.5.5 Interference 165
3.5.6 Rack and Pinion 166
3.5.7 Helical Gears 166
3.5.8 Gear Trains 167
3.6 Dynamic Analysis of Slider Crank Mechanism 168
3.6.1 Motion in Links 169
3.6.2 Dynamic Forces 169
3.6.3 Turning Moment 170
3.7 Flywheel 170
3.7.1 Mean Speed of Rotation 170
3.7.2 Energy Fluctuation 170
CONTENTS xxiii
3.7.3 Turning Moment Diagrams 170
3.8 Belt Drive 171
3.8.1 Types of Belt Drives 171
3.8.2 Length of Belts 171
3.8.3 Power Transmission 172
3.8.4 Crowning of Pulleys 173
3.8.5 Law of Belting 174
3.8.6 Elastic Creep 174
3.8.7 V-Belts 174
3.9 Friction 174
3.9.1 Theory of Friction 174
3.9.2 Inclined Plane 175
3.9.3 Friction in Screw Threads 176
3.9.4 Pivots and Collars 178
3.9.5 Friction Clutches 179
3.10 Governor 179
3.10.1 Types of Governors 179
3.10.2 Sensitiveness and Stability 181
3.10.3 Controlling Force 182
Important Formulas 183
Solved Examples 185
GATE Previous Years’ Questions 188
Multiple Choice Questions 205
Numerical Answer Questions 217
Answers 219
Explanations and Hints 219
4 Vibrations 237
4.1 Fundamentals 237
4.1.1 Basic Phenomenon 237
4.1.2 Harmonic Motion 237
4.1.3 Work Done per Cycle 238
4.1.4 Superposing Waves 239
4.1.5 Classification of Vibrations 239
4.1.6 Elements of Vibration Systems 240
4.2 Undamped Free Vibration 244
4.2.1 Equilibrium Method 244
4.2.2 Energy Method 245
4.2.3 Rayleigh’s Energy Method 246
4.3 Free Damped Vibration 247
4.3.1 Over-Damped System 248
4.3.2 Critically Damped System 248
4.3.3 Under-Damped System 248
4.4 Forced Vibration 249
4.4.1 Spring–Mass–Damper System 249
4.4.2 Rotating Unbalance 252
4.4.3 Support Excitation 253
xxiv CONTENTS
4.4.4 Transmissibility 253
4.4.5 Whirling of Rotating Shafts 254
Important Formulas 255
Solved Examples 256
GATE Previous Years’ Questions 259
Multiple Choice Questions 266
Numerical Answer Questions 272
Answers 273
Explanations and Hints 273
5 Design 283
5.1 Static Loading 283
5.1.1 Modes of Failure 283
5.1.2 Factor of Safety 284
5.1.3 Static Failure Theories 284
5.2 Dynamic Loading 287
5.2.1 Fatigue Failure 287
5.2.2 Stress Cycle 288
5.2.3 Stress Concentration 288
5.2.4 Notch Sensitivity 288
5.2.5 Hysteresis of Stress 288
5.2.6 Endurance Limit 288
5.2.7 Design for Finite Life 289
5.2.8 Cumulative Damage Criteria 289
5.2.9 Fatigue Failure Criterion 289
5.3 Riveted Joints 290
5.3.1 Rivets 290
5.3.2 Caulking and Fullering 290
5.3.3 Terminology 290
5.3.4 Failure of Rivet Joints 291
5.4 Welded Joints 292
5.4.1 Types of Welds 292
5.4.2 Stress in Butt Welds 292
5.4.3 Stress in Fillet Welds 293
5.4.4 Eccentrically Loaded Welds 293
5.4.5 Bending Moment on Welds 293
5.5 Threaded Joints 294
5.5.1 Types of Screw Fastening 294
5.5.2 ISO Thread Designation 294
5.5.3 Stress Analysis of Bolt 295
5.5.4 Eccentric Load on Bolted Joints 295
5.5.5 Elastic Analysis of Bolted Joints 295
5.5.6 Bolt Tightening 296
5.6 Design of Shafts 297
5.6.1 Design for Static Loads 297
5.6.2 Design for Dynamic Loads 298
5.7 Design of Keys 298
CONTENTS xxv
5.7.1 Types of Keys 298
5.7.2 Design of Square and Flat Keys 298
5.8 Design of Gears 299
5.8.1 Standard Systems of Gear Teeth 299
5.8.2 Minimum Number of Teeth 299
5.8.3 Transmitted Load 299
5.8.4 Beam Strength 300
5.8.5 Dynamic Loading 300
5.8.6 Check for Wear 300
5.9 Rolling Contact Bearing 301
5.9.1 Static Load Carrying Capacity 301
5.9.2 Dynamic Load Carrying Capacity 301
5.9.3 Equivalent Dynamic Load 301
5.9.4 Reliability 301
5.9.5 Load Life Relation 301
5.9.6 Cyclic Loads 301
5.10 Sliding Contact Bearing 302
5.10.1 Thick Film Lubrication 302
5.10.2 Thin Film Lubrication 302
5.10.3 Design Considerations 302
5.11 Brakes and Clutches 303
Important Formulas 304
Solved Examples 305
GATE Previous Years’ Questions 309
Multiple Choice Questions 320
Numerical Answer Questions 326
Answers 328
Explanations and Hints 328
PART II FLUID MECHANICS & THERMAL SCIENCES 337
6 Fluid Mechanics 339
6.1 Fluid Properties 339
6.1.1 Mass Density 339
6.1.2 Specific Weight 339
6.1.3 Specific Volume 339
6.1.4 Specific Gravity 339
6.1.5 Viscosity 340
6.1.6 Vapor Pressure 343
6.1.7 Compressibility 343
6.1.8 Surface Tension 344
6.2 Fluid Pressure 346
6.2.1 General Equation 346
6.2.2 Variation in Atmospheric Pressure 347
6.2.3 Pascal’s Law 347
6.2.4 Pressure Nomenclature 348
6.2.5 Pressure Measurements 348
xxvi CONTENTS
6.2.6 Hydrostatic Forces 349
6.3 Buoyancy and Floatation 351
6.3.1 Archimedes Principle 352
6.3.2 Principles of Flotation 352
6.4 Solid Body Motions 354
6.4.1 Linear Acceleration 354
6.4.2 Angular Rotation 355
6.5 Kinematics of Fluid Flow 356
6.5.1 Fluid Velocity 356
6.5.2 Fluid Acceleration 357
6.5.3 Types of Fluid Flow 358
6.5.4 Fluid Flow Lines 359
6.6 Motion of Fluid Particles 359
6.6.1 Rotation 360
6.6.2 Shear Strains 360
6.6.3 Circulation 360
6.6.4 Vorticity 361
6.6.5 Stream Function 361
6.6.6 Velocity Potential 362
6.7 Principles of Fluid Flow 363
6.7.1 Conservation of Mass 363
6.7.2 Conservation of Energy 364
6.7.3 Conservation of Momentum 365
6.8 Flow Measurements 366
6.8.1 Venturimeter 366
6.8.2 Orifice Meter 367
6.8.3 Nozzle Meter 367
6.8.4 Rotameter 367
6.8.5 Elbowmeter 367
6.8.6 Pitot Tube 368
6.9 Vortex Motion 368
6.10 Flow from a Line Source 369
6.11 Laminar Pipe Flow 369
6.11.1 Velocity Profile 370
6.11.2 Discharge 371
6.11.3 Piezometric Head Gradient 371
6.11.4 Shear Stress 371
6.11.5 Power Transmission 372
6.11.6 Losses in Pipe Flow 372
6.11.7 Equivalent Length 373
6.11.8 Water Hammer 373
6.12 Stokes’ Law 373
6.13 Boundary Layer Theory 374
6.13.1 Boundary Layer Thicknesses 374
6.13.2 Laminar Boundary Layer 375
6.13.3 Turbulent Boundary Layer 376
6.13.4 Flow Separation 376
CONTENTS xxvii
Important Formulas 377
Solved Examples 379
GATE Previous Years’ Questions 382
Multiple Choice Questions 397
Numerical Answer Questions 410
Answers 411
Explanations and Hints 411
7 Heat Transfer 427
7.1 Modes of Heat Transfer 427
7.2 Conduction 427
7.2.1 Fourier’s Law 427
7.2.2 Fourier’s Equation 428
7.2.3 Thermal Resistance 429
7.2.4 Variable Thermal Conductivity 430
7.2.5 Critical Radius of Insulation 431
7.2.6 Heat Generation 432
7.2.7 Rectangular Fins 434
7.2.8 Transient Heat Conduction 436
7.3 Convection 438
7.3.1 Newton’s Law of Cooling 438
7.3.2 Dimensionless Numbers 439
7.3.3 Forced Convection 440
7.3.4 Natural Convection 441
7.3.5 Boundary Layer Analogies 442
7.4 Radiation 442
7.4.1 Basic Definitions 442
7.4.2 Intensity of Radiation 443
7.4.3 Lambert’s Cosine law 443
7.4.4 Hemispherical Emissive Power 444
7.4.5 Planck’s Distribution Law 444
7.4.6 Wein’s Displacement Law 444
7.4.7 Stefan-Boltzmann Law 444
7.4.8 Emissivity 445
7.4.9 Kirchhoff’s Law 445
7.4.10 Net Radiation 445
7.4.11 Shape Factor 446
7.4.12 Electrical Network Analogy 447
7.4.13 Heat Shields 448
7.5 Heat Exchanger 448
7.5.1 Types of Heat Exchangers 448
7.5.2 Heat Transfer Coefficients 449
7.5.3 Heat Exchanger Analysis 449
7.5.4 LMTD Method 449
7.5.5 NTU Method 451
Important Formulas 455
Solved Examples 457
xxviii CONTENTS
GATE Previous Years’ Questions 459
Multiple Choice Questions 475
Numerical Answer Questions 485
Answers 486
Explanations and Hints 486
8 Thermodynamics 499
8.1 Basic Concepts 499
8.1.1 Thermodynamic Approaches 499
8.1.2 Thermodynamic Systems 500
8.1.3 State Properties 501
8.1.4 Thermodynamic Equilibrium 501
8.1.5 Two Property Rule 502
8.1.6 Processes and Cycle 502
8.1.7 Modes of Energy 502
8.1.8 Equilibrium in Processes 503
8.2 Zeroth Law of Thermodynamics 504
8.3 Energy Transfer 504
8.3.1 Heat Transfer 504
8.3.2 Work Transfer 505
8.4 First Law of Thermodynamics 505
8.4.1 Expressions of First Law 505
8.4.2 Energy - A Property 506
8.4.3 Enthalpy 507
8.4.4 Specific Heats 507
8.4.5 Steady Flow Systems 508
8.4.6 Unsteady Flow Systems 510
8.5 Second Law of Thermodynamics 511
8.5.1 Energy Reservoirs 511
8.5.2 Cyclic Heat Engine 511
8.5.3 Refrigerator 512
8.5.4 Heat Pump 512
8.5.5 Statements of Second Law 513
8.5.6 Reasons of Irreversibility 513
8.5.7 Carnot Cycle 513
8.5.8 Carnot Principles 514
8.5.9 Celsius Scale 514
8.5.10 Perfect Gas Scale 515
8.5.11 Absolute Temperature Scale 515
8.5.12 Reversible Adiabatic Paths 516
8.5.13 Clausius Theorem 516
8.5.14 Entropy - A Property 517
8.5.15 Clausius Inequality 517
8.5.16 The Increase of Entropy Principle 518
8.5.17 Isentropic Processes 519
8.5.18 Perpetual Motion Machines 519
8.6 Third Law of Thermodynamics 519
CONTENTS xxix
8.7 Exergy and Irreversibility 519
8.7.1 Dead State 520
8.7.2 Useful Work 520
8.7.3 Exergy 520
8.7.4 Availability Function 521
8.7.5 Irreversibility 521
8.8 Properties of Gases 521
8.8.1 Pure Substance 522
8.8.2 Ideal Gas Equation of State 522
8.8.3 Compressibility Factor 522
8.8.4 Principle of Corresponding States 523
8.8.5 Van der Waals Equation 523
8.8.6 Entropy Change of Ideal Gases 524
8.8.7 Reversible Processes 524
8.8.8 Properties of Gas Mixtures 528
8.9 Gas Compression 529
8.9.1 Shaft Work 529
8.9.2 Volumetric Efficiency 530
8.9.3 Staged Compression 530
8.10 Brayton Cycle 531
8.10.1 Thermal Efficiency 531
8.10.2 Maximum Work Output 532
8.10.3 Isentropic Efficiencies 533
8.10.4 Regeneration 533
8.10.5 Intercooling and Reheat 534
8.10.6 Comparison with Otto Cycle 534
Important Formulas 535
Solved Examples 537
GATE Previous Years’ Questions 539
Multiple Choice Questions 553
Numerical Answer Questions 563
Answers 565
Explanations and Hints 565
9 Applications 579
9.1 Power Engineering 579
9.1.1 Properties of Steam 579
9.1.2 Steam Flow through Nozzle 584
9.1.3 Rankine Cycle 587
9.1.4 Steam Turbines 590
9.2 Internal Combustion Engines 595
9.2.1 Fundamentals 595
9.2.2 Air Standard Cycles 596
9.2.3 Working Principles 604
9.2.4 Fuel Air Cycles 606
9.2.5 Carburation 607
9.2.6 Combustion in SI Engines 608
xxx CONTENTS
9.2.7 Combustion in CI Engines 608
9.2.8 Knock Rating of Fuels 609
9.2.9 Performance Analysis 609
9.2.10 Combustion Reactions 611
9.3 Refrigeration and Air Conditioning 612
9.3.1 Refrigerants 612
9.3.2 Air Refrigeration Cycles 613
9.3.3 Vapor Compression System 614
9.3.4 Psychrometry 615
9.3.5 Air Conditioning 620
9.4 Turbomachinery 621
9.4.1 Fundamentals 621
9.4.2 Pelton Wheel 623
9.4.3 Francis Turbine 624
9.4.4 Kaplan Turbine 625
9.4.5 Turbine Characteristics 626
9.4.6 Centrifugal Pump 627
Important Formulas 630
Solved Examples 632
GATE Previous Years’ Questions 635
Multiple Choice Questions 657
Numerical Answer Questions 672
Answers 673
Explanations and Hints 673
PART III MANUFACTURING & INDUSTRIAL ENGINEERING 689
10 Engineering Materials 691
10.1 Atomic Structure 691
10.2 Crystal Structure 692
10.2.1 Lattice and Unit Cells 692
10.2.2 Crystal Systems 692
10.2.3 Anisotropy and Isotropy 693
10.2.4 Characteristics of Cells 693
10.2.5 Crystal Structure of Metals 693
10.3 Crystal Imperfections 694
10.3.1 Point Defects 694
10.3.2 Line Defects 695
10.3.3 Planar Defects 696
10.3.4 Bulk Defects 697
10.4 Effects of Imperfections 697
10.5 Grain Formation 698
10.6 Grain Size Measurement 698
10.7 Grain Structure 698
10.7.1 Recovery 698
10.7.2 Recrystallization 699
10.7.3 Grain Growth 699
CONTENTS xxxi
10.8 Deformation 699
10.8.1 Types of Deformation 699
10.8.2 Stress–Strain Relationship 700
10.8.3 Strain Hardening 700
10.8.4 Deformation Mechanisms 700
10.9 Multiphase Structure 701
10.9.1 Phase 701
10.9.2 Solid Solution 701
10.9.3 Gibbs Free Energy 702
10.9.4 Phase Diagrams 702
10.9.5 Eutectic Microstructure 704
10.9.6 Invariant Reactions 704
10.10 Iron-Carbon Phase 705
10.10.1 Phase Components 705
10.10.2 Invariant Reactions 706
10.10.3 TTT Diagram 707
10.11 Heat Treatment of Steel 708
10.11.1 Hardening 708
10.11.2 Tempering 708
10.11.3 Austempering 708
10.11.4 Martempering 708
10.11.5 Annealing 709
10.11.6 Stress Relieving 709
10.11.7 Spheroidizing 709
10.11.8 Normalizing 709
10.11.9 Case Hardening 709
10.12 Alloying of Steels 710
10.13 Mechanical Properties 711
10.13.1 Tensile Strength 712
10.13.2 Impact Strength 713
10.13.3 Fatigue Strength 713
10.13.4 Creep 713
10.13.5 Hardness 714
10.14 Engineering Metals 715
10.14.1 Ferrous Materials 715
10.14.2 Non-Ferrous Materials 717
10.15 Ceramics 718
10.15.1 Types of Ceramics 718
10.15.2 Applications 719
10.16 Polymers 719
10.17 Composites 719
Important Formulas 720
Solved Examples 721
GATE Previous Years’ Questions 722
Multiple Choice Questions 724
Numerical Answer Questions 729
Answers 729
xxxii CONTENTS
Explanations and Hints 729
11 Metal Casting 735
11.1 Elements of Casting 735
11.2 Sand Casting 735
11.3 Pattern 736
11.3.1 Pattern Allowances 736
11.3.2 Pattern Materials 737
11.3.3 Pattern Types 737
11.4 Molding Sand 737
11.4.1 Properties of Molding Sand 737
11.4.2 Molding Sand Additives 738
11.5 Gating System 738
11.5.1 Elements of Gating System 738
11.5.2 Pouring Time 739
11.5.3 Aspiration Effect 739
11.5.4 Gating Ratio 740
11.5.5 Cooling and Solidification 740
11.5.6 Design of Riser 740
11.6 Casting Methods 741
11.6.1 Shell Molding 741
11.6.2 Expendable Pattern Casting 741
11.6.3 Investment Casting 742
11.6.4 Permanent Mold Casting 742
11.6.5 Die Casting 742
11.6.6 Centrifugal Casting 742
11.6.7 Slush Casting 742
11.6.8 Continuous Casting 743
11.7 Casting Defects 743
11.8 Inspection of Casting 743
Important Formulas 744
Solved Examples 744
GATE Previous Years’ Questions 746
Multiple Choice Questions 750
Numerical Answer Questions 755
Answers 755
Explanations and Hints 755
12 Forming 761
12.1 Rolling 761
12.2 Forging 763
12.3 Extrusion 764
12.4 Wire Drawing 765
12.5 Sheet Metal Forming 765
12.5.1 Shearing 765
12.5.2 Drawing 766
12.5.3 Spinning 767
CONTENTS xxxiii
12.5.4 Bending 767
12.5.5 Stretch Forming 768
12.5.6 Embossing 768
12.5.7 Coining 768
12.6 High-Energy Rate Forming 768
12.7 Powder Metallurgy 769
12.7.1 Process Details 769
12.7.2 Applications 769
Important Formulas 770
Solved Examples 770
GATE Previous Years’ Questions 772
Multiple Choice Questions 778
Numerical Answer Questions 783
Answers 784
Explanations and Hints 784
13 Joining 791
13.1 Welding 791
13.1.1 Oxyacetylene Gas Welding 791
13.1.2 Electric Arc Welding 792
13.1.3 Resistance Welding 795
13.1.4 Solid State Welding Processes 797
13.1.5 Advance Welding Techniques 797
13.2 Brazing 798
13.3 Soldering 798
Important Formulas 799
Solved Examples 799
GATE Previous Years’ Questions 800
Multiple Choice Questions 804
Numerical Answer Questions 809
Answers 809
Explanations and Hints 809
14 Machining 815
14.1 Mechanism of Metal Cutting 815
14.1.1 Chip Formation 815
14.1.2 Built Up Edge 816
14.1.3 Chip Thickness Ratio 817
14.1.4 Shear Angle 817
14.1.5 Shear Strain 817
14.1.6 Chip Velocity 817
14.1.7 Shear Velocity 817
14.1.8 Shear Strain Rate 818
14.1.9 Ernst–Merchant Analysis 818
14.2 Cutting Heat 819
14.3 Tool Materials 819
14.4 Cutting Fluids 820
xxxiv CONTENTS
14.5 Cutting Tool Geometry 820
14.6 Machinability 821
14.6.1 Tool Life 821
14.6.2 Surface Finish 823
14.7 Economics of Machining 824
14.8 Machining Processes 825
14.8.1 Shaping 825
14.8.2 Turning 825
14.8.3 Drilling 826
14.8.4 Milling 827
14.8.5 Grinding 827
14.9 Finishing Operations 828
14.9.1 Honing 828
14.9.2 Lapping 828
14.9.3 Reaming 828
14.9.4 Broaching 829
14.9.5 Tapping 829
14.10 Modern Machining Processes 829
14.10.1 Abrasive-Jet Machining 829
14.10.2 Ultrasonic Machining 830
14.10.3 Electrochemical Machining 831
14.10.4 Electric-Discharge Machining 832
14.10.5 Electron-Beam Machining 834
14.10.6 Laser-Beam Machining 834
14.10.7 Plasma-Arc Machining 835
14.11 Jigs and Fixtures 835
Important Formulas 836
Solved Examples 837
GATE Previous Years’ Questions 839
Multiple Choice Questions 850
Numerical Answer Questions 856
Answers 857
Explanations and Hints 857
15 Metrology and Inspection 865
15.1 Limits, Tolerances, and Fits 865
15.1.1 Limit Systems 865
15.1.2 Tolerance Systems 866
15.1.3 Fits 866
15.1.4 IS:919-1963 867
15.2 Linear Measurement 867
15.3 Angular Measurement 869
15.4 Gauge Design 870
15.5 Interferometry 871
15.6 Surface Measurement 871
Important Formulas 872
Solved Examples 872
CONTENTS xxxv
GATE Previous Years’ Questions 873
Multiple Choice Questions 877
Numerical Answer Questions 881
Answers 881
Explanations and Hints 882
16 Computer Integrated Manufacturing 887
16.1 Computer Integrated Manufacturing 887
16.2 Computer Aided Design 887
16.3 Computer Aided Manufacturing 888
16.4 Integration of CAD and CAM Systems 888
16.5 Numerical Control 889
16.5.1 NC Machine Tools 889
16.5.2 Principle of Operation 889
16.5.3 Coordinate Systems 889
16.5.4 Motion Control Systems 889
16.5.5 NC Positioning Systems 890
16.5.6 Manual NC Part Programming 891
16.5.7 Merits of NC 892
16.5.8 Demerits of NC 892
16.6 Group Technology 892
Important Formulas 893
Solved Examples 893
GATE Previous Years’ Questions 894
Multiple Choice Questions 897
Numerical Answer Questions 899
Answers 899
Explanations and Hints 899
17 Production Planning & Control 903
17.1 Functions of PPC 903
17.1.1 Production Planning 904
17.1.2 Production Control 904
17.2 Forecasting 905
17.2.1 Forecasting Methods 905
17.2.2 Forecasting Errors 907
17.3 Aggregate Planning 907
17.4 Disaggregation 907
17.5 Material Requirement Planning 908
17.6 Break-even Point Analysis 908
17.7 Lot Sizing Rules 909
17.8 Assembly Line Balancing 909
Important Formulas 910
Solved Examples 910
GATE Previous Years’ Questions 911
Multiple Choice Questions 915
Numerical Answer Questions 918
xxxvi CONTENTS
Answers 918
Explanations and Hints 918
18 Inventory Control 923
18.1 Basic Concepts 923
18.1.1 Types of Inventory 923
18.1.2 Costs of Inventory 924
18.1.3 Inventory Demand 924
18.1.4 Inventory Replenishment 924
18.1.5 Inventory Control Systems 924
18.2 EOQ Models 925
18.2.1 Simple EOQ Model 925
18.2.2 Build-Up EOQ Model 926
18.3 Probabilistic Inventory Models 926
18.4 Selective Approaches 927
18.5 Just-In-Time Production 927
Important Formulas 928
Solved Examples 928
GATE Previous Years’ Questions 929
Multiple Choice Questions 933
Numerical Answer Questions 937
Answers 937
Explanations and Hints 937
19 Operations Research 943
19.1 Simplex Method 943
19.1.1 Problem Definition 943
19.1.2 Conditions for Applicability 944
19.1.3 Simplex Algorithm 944
19.1.4 Exceptional Cases 946
19.1.5 Duality 947
19.1.6 Limitations of Simplex Method 947
19.2 Transportation Problem 947
19.2.1 Problem Definition 947
19.2.2 Solution Procedure 948
19.2.3 Exceptional Cases 949
19.3 Assignment Problem 950
19.3.1 Problem Definition 950
19.3.2 Solution of Problem 950
19.3.3 Exceptional Cases 951
19.4 Sequencing 951
19.4.1 Problem Definition 951
19.4.2 Solution of Problem 951
19.5 Queuing Theory 952
19.5.1 Elements of Queuing Models 952
19.5.2 Model (M/M/1):(∞/FCFS) 953
19.6 PERT and CPM 954
CONTENTS xxxvii
19.6.1 Project Network Components 955
19.6.2 Critical Path 955
19.6.3 Activity Float Analysis 956
19.6.4 Time-Cost Trade-Off Analysis 956
Important Formulas 957
Solved Examples 958
GATE Previous Years’ Questions 962
Multiple Choice Questions 973
Numerical Answer Questions 979
Answers 979
Explanations and Hints 980
Question Bank for Practice 987
Multiple Choice Questions 987
Numerical Answer Questions 990
Answers 992
Explanations and Hints 992
Index 999