Description : Give One Example Each Of The Following Proportion Of Materials – Dimensional, Physical, Technological And Mechanical?
Last Answer : Roughness, enthalpy, toughness and hardness respectively.
Description : Which Theories Of Failure Are Used For? (a) Ductile Materials (b) Brittle Materials?
Last Answer : For ductile materials, theories of failure used are maximum shear stress theory and maximum energy of distortion theory; For brittle materials, the theory of maximum principal stress and maximum strain are used.
Description : Whether Individual Components In Composite Materials Retain Their Characteristics Or Not?
Last Answer : Yes.
Description : Specific Strength Of Materials Is Very High When They Are In Fibre Size But Lower When They Are In Bar Form - Why?
Last Answer : The crystal structure has ordered, repeating arrangement of atoms. Fibers are liable to maintain this and thus have high specific strength. As for size increases, the condition of ordered and ... because of several types of defects and dislocations, and thus the specific strength gets lower.
Description : What Are Orthotropic Materials?
Last Answer : Orthotropic materials are a special class of isotropic materials which can be described by giving their properties in three perpendicular directions ex: wood; composites.
Description : Strong and ductile materials (a) Polymers (b) Ceramics (c) Metals (d) Semiconductors
Last Answer : (c) Metals
Description : Not an example for actuator (a) Optical fiber (b) Shape memory alloys (c) Magneto-strictive materials (d) Electro-/Magneto-rheological fluids
Last Answer : (a) Optical fiber
Description : Which one of the following is not basic component of Materials Science? (a) Cost (b) Properties (c) Structure (d) Performance
Last Answer : (a) Cost
Description : Explain The Difference Between Pear Lite And Cementite?
Last Answer : Pearlite is a eutectoid mixture of ferrite and cementite. Cementide is a chemical compound of iron and carbon.
Description : When A Material Is Known As Allotropy Or Polytropic?
Last Answer : A material is known as allotropic aur polytropic if it exists in several forms at a different temperature.
Description : What Is Allot Rope? In What Forms Of Cubic Pattern, Iron Exists?
Last Answer : Some elements exist in more than one crystalline form. Each crystalline form is known as ‘allotrope’ of the element. Iron exists in two crystalline forms of cubic pattern, namely, bodycentered cubic (BCC) and face-centered cubic (FCC).
Description : Hydrogen Cannot Be Removed Easily From Molten Steel. What Harm Hydrogen Has On Property Of Steel?
Last Answer : Excessive hydrogen in molten steel results in the formation of small fissures often described as hairline cracks or flakes in the steel. Large forgings an alloy steel are particularly sensitive to this phenomenon.
Description : How Oxygen Gas Can Be Removed From Steel During Melting? What Are Fully Killed Steel?
Last Answer : Oxygen gas can be removed from steel during melting by adding elements such as manganese, silicon or aluminium which, because of their high affinity for oxygen, react with it to form non-metallic ... Steels in which have has most of their dissolved oxygen removed are called fully killed steels'.
Description : For Which Parts The Wahl Factor And Lewis Factor Is Used?
Last Answer : Wahl factor and Lewis factor is used for springs and gears respectively.
Description : What Is The Name Of Solid Solution Of Carbon In Alpha-iron And Delta Iron?
Last Answer : Ferrite and Austenite respectively.
Description : Give One Example Of Metal Classified As Per Structure As Bcc, Fcc, Hcp And Ccp?
Last Answer : Examples of BCC, FCC, HCP and CCP structures: BCC (Body Centred Cubic) structure – molybdenum; FCC (Face Centred Cubic) structure – Aluminum; HCP (Hexagonal Close Packed) structure – Zinc; CCP (Cubic Close Packing) structure – Copper.
Description : Define Ceramic?
Last Answer : Ceramic is a solid formed by the combination of metallic and non-metallic elements.
Description : What Does The Alloy Designation Fg 250 Indicate?
Last Answer : FG 250 alloy designation indicates Grey cast iron with a tensile strength of 250 MPa.
Description : What Is The Common Element Between The Brass And Bronze Metal Alloys?
Last Answer : Copper.
Description : List At Least Two Factors That Promote The Transition From Ductile To Brittle Fracture?
Last Answer : The manner of loading and the rate of loading promote the transition from ductile to brittle fracture. A machine member may have ductile failure under static loading but may fail in brittle fashion when the ... testing speed, but if the load is applied at a high velocity then failure may be brittle.
Description : While Normal Carburizing And Nit Riding Surface Treatments Increase Fatigue Strength, Excessive Treatment May Decrease The Fatigue Strength. Why?
Last Answer : Normal carburizes/nits riding treatments increases volume due to phase transformation at the surface and introduce residual compressive surface stress and thus increases fatigue strength. By excessive treatment, the ... in the regions of the high tensile stress and lead o early fatigue failure.
Description : Distinguish Between Creep And Fatigue?
Last Answer : Creep is low and progressive deformation of a material with time under a constant stress at high-temperature applications. Fatigue is the reduced tendency of material to offer resistance to applied stress under repeated or fluctuating loading condition.
Description : Why Fatigue Strength Decreases As Size Of A Part Increases Beyond Around 10mm?
Last Answer : The perfection of material conditions is possible at lower sizes, and as size increases, it is not possible to attain a uniform structure of the material.
Description : Why Is It That The Maximum Value Which The Residual Stress Can Reach Is The Elastic Limit Of The Material?
Last Answer : A stress more than the elastic limit, with no external force to oppose it, we relieve itself by plastic deformation until it reaches the value of the yield stress.
Description : Which Element Is Added In Steel To Increase Resistance To Corrosion?
Last Answer : Chromium.
Description : What Is The Percentage Of Carbon In Cast Iron?
Last Answer : 2.5%.
Description : What Is Curie Point?
Last Answer : Curie point is the temperature at which ferromagnetic materials can no longer be magnetized by outside forces.
Description : What Are The Principal Constituents Of Brass?
Last Answer : Principal constituents of brass are copper and zinc.
Description : Mention Two Types Of Dislocations?
Last Answer : Dislocation refers to a break in the continuity of the lattice. In an edge dislocation, one plane of atoms gets squeezed out. In screw dislocation, the lattice atoms move from their regular ideal positions.
Description : Explain The Effects Of Alloying Chromium And Nickel In Stainless Steel.?
Last Answer : The addition of nickel and chromium increases the tensile strength and increase in resistance to corrosion takes place.
Description : What Properties Are Needed To Be Considered For Application Calling For Following Requirements? I) Rigidity. Ii) Strength Of No Plastic Deformation Under Static Load. Iii) Strength To Withstand Overload Without Fracture.
Last Answer : i) Reliability – elastic modulus and yield strength. ii) Strength (for no plastic deformation under static loading) – yield point. iii) Strength (overload) – Toughness and impact resistance. iv) Wear resistance – Hardness. v) Reliability and safety – Endurance limit and yield.
Description : A Plain Carbon Steel Has Brinell Hardness Number (bhn) Of 180. What Are The Values Of Rc, Vhn And Ultimate Strength?
Last Answer : Rc = BHN/10 = 18, VHN = BHN = 180 Ultimate strength = 3.48 × BHN MPa = 620 MPa.
Description : Democratic material (a) Diamond (b) Titanium (c) Iron (d) Gold
Last Answer : (c) Iron
Description : Detrimental property of a material for shock load applications (a) High density (b) Low toughness (c) High strength (d) Low hardness
Last Answer : (b) Low toughness
Description : Presently most used metal in the world (a) Aluminium (b) Gold (c) Steel (d) Silver
Last Answer : (c) Steel
Description : Pick the composite from the list (a) Wood (b) Steel (c) Nylon (d) Mica
Last Answer : (a) Wood
Description : Figure out the odd statement about ceramics in the following (a) Good insulators of heat and electricity (b) Usually less desire than metals (c) Ductile in nature (d) Contains both metallic and nonmetallic elements
Last Answer : (c) Ductile in nature
Description : First metal known to be used by man (a) Iron (b) Bronze (c) Silver (d) Aluminium
Last Answer : (b) Bronze
Description : First material known to be used by man (a) Cotton (b) Bronze (c) Iron (d) Rock
Last Answer : (d) Rock
Description : What is the difference between isotropic and anisotropic materials ?
Last Answer : If a material exhibits same mechanical properties regardless of loading direction, it is isotropic, e.g., homogeneous cast materials. Materials lacking this property are anisotropic.
Description : In isotropic materials, which of the following quantities will be independent of the direction? a) Permittivity b) Permeability c) Polarisation d) Polarizability
Last Answer : a) Permittivity
Description : The materials which have the same elastic properties in all directions, are called (A) Isotropic (B) Brittle (C) Homogeneous (D) Hard
Last Answer : (A) Isotropic
Description : Isotropic materials have the same __________ in all directions. (A) Induced stresses (B) Density (C) Elastic properties (D) Thermal properties
Last Answer : C) Elastic properties
Description : What is the difference between isotropic material and homogeneous material ?
Last Answer : In homogeneous material the composition is same throughout and in isotropic material the elastic constants are same in all directions.
Description : Name the protein found in isotropic and anisotriopic bands of myofibrils
Last Answer : Name the protein found in isotropic and anisotriopic bands of myofibrils
Description : A frosted bulb which may be taken as an isotropic source, gives as illumination of `8lm//m^(2)` at a distance of 5m. Calculate (i) its luminous intens
Last Answer : A frosted bulb which may be taken as an isotropic source, gives as illumination of `8lm//m^(2)` ... and (ii) the total luminous flux from the blub.
Description : What is isotropic material ?
Last Answer : It is a material having same elastic constants in all directions.
Description : It is useful to refer to an isotropic radiator. A. when comparing the gains of directional antennas B. when testing a transmission line for standing wave ratio C. when (in the northern hemisphere) directing the transmission D. when using a dummy load to tune a transmitter
Last Answer : A. when comparing the gains of directional antennas
Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB
Last Answer : C. 3.9 dB