Engineering Physics-II

Description

Title Contents 1. Conducting Materials 1.1 Introduction 1.2 Conduction in Metals 1.2.1 Drift Velocity of Free Electrons 1.2.2 Current Density 1.2.3 Electrical Conductivity 1.2.4 Mobility 1.2.5 Mean Free Path 1.2.6 Mean Free Time 1.2.7 Relaxation Time 1.3 Classical Free Electron Theory of Metals 1.3.1 Postulates of Classical Free Electron Theory 1.4 Electrical Conductivity 1.4.1 Application of Kinetic Theory of Gases to Free Electrons 1.5 Factors Affecting the Resistivity of Metals 1.5.1 Dependence on Temperature 1.5.2 Dependence on Impurity Concentration 1.5.3 Dependence on Strain 1.5.4 Dependence on Magnetic Field 1.6 Thermal Conductivity 1.7 Wiedemann–Franz Law 1.8 Merits of Classical Free Electron Theory 1.9 Drawbacks of Classical Free Electron Theory 1.10 Quantum Free Electron Theory of Metals 1.11 Fermi–Dirac Distribution Function 1.11.1 Temperature Dependence of Fermi Energy 1.11.2 Average Energy of Free Electrons at T = 0 K 1.11.3 Average Energy of a Free Electron at T ≠ 0 K 1.12 Density of States 1.13 Carrier Concentration in Metals 1.14 Energy Distribution of Electrons Solved Examples Questions and Answers Exercise Problems Questions 2. Semiconducting Materials 2.1 Introduction 2.2 Types of Semiconductors 2.2.1 Classification I 2.2.2 Classification II 2.2.3 Classification III 2.3 Intrinsic Semiconductors 2.3.1 Intrinsic Carrier Concentration 2.3.2 Electron Concentration in Conduction Band 2.3.3 Hole Concentration in the Valence Band 2.3.4 Fermi Level in an Intrinsic Semiconductor 2.3.5 Variation of Fermi Level with Temperature 2.3.6 Carrier Concentration 2.3.7 Intrinsic Electrical Conductivity 2.3.8 Bandgap Determination 2.4 Extrinsic Semiconductors 2.4.1 n-Type Semiconductors 2.4.2 Energy Band Structure of n-type Semiconductors 2.4.3 Electron Concentration in Conduction Band of n-Type Semiconductor 2.4.4 Variation of Fermi Level with Temperature and Impurity Concentration 2.4.5 Carrier Concentration 2.4.6 p-Type Semiconductors 2.4.7 Energy Band Structure of p-Type Semiconductors 2.4.8 Hole Concentration in Valence Band of p-type Semiconductor 2.4.9 Variation of Fermi Level with Temperature and Impurity Concentration 2.4.10 Carrier Concentration 2.4.11 Law of Mass Action 2.4.12 Physical Interpretation of Effective Mass 2.4.13 Fermi Energy Level 2.4.14 Electrical Conductivity of an Extrinsic Semiconductor 2.5 Hall Effect 2.5.1 Determination of Hall Coefficient 2.5.2 Hall Angle 2.5.3 Experimental Determination of Hall Coefficient 2.5.4 Applications of Hall Effect 2.6 Semiconductor Devices 2.6.1 Solar Cell 2.6.2 Construction 2.6.3 Principle of Power Generation 2.6.4 Quantum Efficiency 2.6.5 Methods to Increase Efficiency 2.6.6 Advantages 2.6.7 Disadvantages 2.6.8 Applications 2.6.9 LDR 2.6.10 Characteristics 2.6.11 Applications Solved Examples Questions and Answers Exercise Problems Questions 3. Magnetic and Superconducting Materials 3.1 Introduction—Origin of Magnetic Moment 3.2 Magnetic Induction (B) 3.3 Magnetic Dipoles or Magnetic Moment 3.4 Bohr Magneton Theory 3.5 Intensity of Magnetization (I) 3.6 Magnetic Field Intensity (H) 3.7 Magnetic Susceptibility (c) 3.8 Magnetic Permeability (m) 3.9 Classification of Magnetic Materials 3.10 Diamagnetic Materials 3.10.1 Characteristics of Diamagnetic Materials 3.11 Paramagnetic Materials 3.11.1 Characteristics of Paramagnetic Materials 3.12 Ferromagnetic Materials 3.12.1 Characteristics of Ferromagnetic Materials 3.13 Antiferromagnetic Materials 3.13.1 Characteristics of Antiferromagnetic Materials 3.14 Ferrimagnetic Materials 3.14.1 Characteristics of Ferrimagnetic Materials 3.15 Variation of Susceptibility with Temperature in Different Magnetic Materials 3.16 Domain Theory of Ferromagnetism 3.16.1 Magnetic Domains 3.16.2 Process of Domain Magnetisation 3.16.3 Motion of Domain Walls 3.16.4 Rotation of Domains 3.16.5 Types of Energy Involved in the Process of Domain Growth 3.17 Reversible and Irreversible Domains 3.18 Hysteresis 3.19 Soft and Hard Magnetic Materials 3.19.1 Soft Magnetic Materials 3.19.2 Hard Magnetic Materials 3.20 Ferrites 3.20.1 Structure of Ferrites 3.20.2 Types of Structures 3.20.3 Preparation 3.20.4 Powder Preparation 3.20.5 Mixing 3.20.6 Compacting 3.20.7 Sintering 3.20.8 Properties of Ferrites 3.20.9 Applications of Ferrites 3.21 Magneto-optical Recording and Read Out 3.21.1 Recording Process 3.21.2 Read-out Process 3.21.3 Erasure Process 3.22 Magnetic Storage 3.22.1 Magnetic Tape 3.22.2 Floppy Disks (Diskettes) 3.23 Magnetic Disc Drives 3.24 Magnetic Devices 3.24.1 Transformer 3.24.2 Transformer Core 3.24.3 Characteristics of a Core 3.24.4 Types of a Transformer Core 3.24.5 Hollow Core Transformers 3.24.6 Shell Core Transformers 3.24.7 Requirement of a Transformer Core 3.25 Superconducting Materials—Introduction 3.25.1 Properties of Superconductors 3.25.2 Types of Superconductors 3.25.3 BCS Theory of Superconductivity 3.25.4 Applications of Superconductors 3.25.5 Cryotron 3.25.6 Superconducting Levitation 3.25.7 Superconducting Quantum Interference Device (SQUID) 3.25.8 High Temperature Superconductors 3.25.9 Crystal Structure of High Tc Ceramic Superconductors Solved Examples Questions and Answers Exercise Problems Questions 4. Dielectric Materials 4.1 Introduction 4.2 Characteristic Parameters of Dielectrics 4.2.1 Dielectric Constant 4.2.2 Electric Dipole Moment 4.2.3 Polarization 4.2.4 Electric Susceptibility 4.2.5 Polarizability 4.3 Different Types of Polarization 4.3.1 Electronic or Induced Polarization (ae) 4.3.2 Atomic or Ionic Polarization (ai) 4.3.3 Orientation Polarization (a0) 4.3.4 Space Charge Polarization or Interfacial Polarization (as) 4.3.5 Total Polarization of a Dielectric Material 4.4 Frequency Dependence of Polarization 4.5 Temperature Dependence of Polarization 4.6 Internal Field 4.7 Clausius–Mosotti Equation 4.8 Dielectric Loss 4.9 Determination of Dielectric Constant 4.10 Dielectric Breakdown 4.10.1 Types of Dielectric Breakdown 4.11 Uses of Dielectric Materials 4.11.1 Solid Insulating Materials—Capacitors 4.11.2 Liquid Insulating Materials—Transformers 4.12 Ferroelectric Materials 4.12.1 Properties 4.12.2 Applications Solved Examples Questions and Answers Exercise Problems Questions 5. Modern Engineering Materials 5.1 Introduction 5.2 Metallic Glasses 5.2.1 Preparation 5.2.2 Properties 5.2.3 Applications of Metallic Glasses 5.3 Shape Memory Alloys 5.3.1 Crystal Structure of Shape Memory Alloys 5.3.2 Pseudo-elasticity 5.3.3 Hysteresis 5.3.4 Training Shape Memory Alloys 5.3.5 Thermomechanical Behaviour 5.3.6 Alloys having Shape Memory Effect 5.3.7 Characteristics and Properties of Ni–Ti Alloy 5.3.8 Physical Properties of Nitinol (Ni-Ti alloy) 5.3.9 Mechanical Properties of Nitinol (Ni-Ti alloy) 5.3.10 Applications and Advantages of Shape Memory Alloys 5.3.11 Disadvantages of SMA 5.4 Nanomaterials 5.4.1 Synthesis 5.4.2 Top-down Processes 5.4.3 Bottom-up Processes 5.4.4 Ball-Milling Method 5.4.5 Lithographic Method 5.4.6 Plasma-assisted Deposition Process 5.4.7 Vapour-phase Deposition Method 5.4.8 Physical Vapour Deposition 5.4.9 Chemical Vapour Deposition 5.4.10 Colloidal Method 5.4.11 Sol–Gel Method 5.4.12 Electrodeposition Method 5.4.13 Properties of Nanomaterials 5.4.14 Variation of Physical Properties with Size 5.4.15 Magnetism in Nanoparticles 5.4.16 Mechanical Behaviour 5.4.17 Other Properties of Nanomaterials 5.4.18 Applications 5.4.19 Other Applications 5.5 Carbon Nanotubes (CNT) 5.5.1 Structure 5.5.2 Type of Carbon Nanotubes 5.5.3 Fabrication of Carbon Nanotubes 5.5.4 Properties of Carbon Nanotubes 5.5.5 Applications of Carbon Nanotubes Questions and Answers Questions Index