Last Answer : Line imperfection in a crystal is called edge dislocation.
Description : Normalising of an object does not (A) Refine coarse grain structure obtained during hot working (B) Improve ductility (C) Improve yield strength (D) Improve mechanical properties
Last Answer : (B) Improve ductility
Description : Which of the following properties is generally found, in non-metals?' (1) Brittleness (2) Conductivity (3) Ductility (4) Malleability
Last Answer : (1) Brittleness Explanation: An important physical property of non metals is that they are brittle and hence cannot be beaten into sheets or drawn into wires. In other words, non-metals are non-malleable and non-ductile. Where stress is applied on nonmetals, they shatter into pieces.
Description : Which of the following physical properties is TRUE of most dense ceramic materials? w) high tensile strength x) good ductility y) high compressive strength z) high electrical conductivity
Last Answer : ANSWER: Y -- HIGH COMPRESSIVE STRENGTH
Description : Which of the following properties is generally found in nonmetals? (1) Brittleness (2) Conductivity (3) Ductility (4) Malleability
Last Answer : Brittleness
Description : In cold working of metal as compared to its hot working (A) Cracks and blow holes are eliminated (B) Ductility and impact strength improves (C) Appreciable strain hardening is produced (D) Yield stress, hardness and fatigue strength is not at all affected
Last Answer : (C) Appreciable strain hardening is produced
Description : Refractory metals are known for which of the following properties: w) lack of chemical reactivity x) low density y) high melting point z) high thermal conductivity
Last Answer : ANSWER: Y -- HIGH MELTING POINT
Description : Which of the following factors affect the mechanical properties of a material under applied loads? a) Content of alloys b) Grain size c) Imperfection and defects d) Shape of material
Last Answer : d) Shape of material
Description : (3) reflection of light due to the presence of free electrons Explanation: Lustre (or luster) is the way light interacts with the surface of a crystal, rock, or mineral. The word ... conductivity, and high density. Typically they are malleable and ductile, deforming -under stress without cleaving.
Last Answer : Cloud is a colloidal dispersion of – (1) Air in a dispersion medium of water (2) Fog in a dispersion medium of water (3) Mist in a dispersion medium of air (4) Water drops in a dispersion medium of air
Description : When the steel is subjected to normalising, its __________ decreases. (A) Yield point (B) Ductility (C) Ultimate tensile strength (UTS)
Last Answer : (B) Ductility
Description : Non-ferrous metals and hard steels do not exhibit a definite yield point, when pulled in the testing machine and hence for these cases, a better measure of their elastic properties is defined by the __________ stress. (A) Ultimate (B) Yield point (C) Proof (D) None of these
Last Answer : (C) Proof
Description : The material used for a fuse wire should have (a) high resistivity (b) high ductility (c) high melting point (d) low melting point
Last Answer : Ans:(d)
Description : The ductility of metal is usually expressed in terms of the: A. Yield strength (point where the material is not longer elastic) B. Percent elongation C. Modulus of elasticity (stiffness of the material)
Last Answer : B. Percent elongation
Description : Reaction between X and Y forms compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z? A) Has high melting point B) Has low melting point C) Conducts electricity in molten state D) Occurs as solid
Last Answer : B) Has low melting point
Description : Presence of 0.3 to 0.5% arsenic in copper increases its (A) Ductility (B) Malleability (C) Tenacity & hardness (D) Electrical conductivity
Last Answer : (C) Tenacity & hardness
Description : Copper has very low (A) Malleability (B) Ductility (C) Tensile strength (D) Thermal & electrical conductivity
Last Answer : (C) Tensile strength
Description : A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity
Last Answer : (A) More corrosion resistant
Description : The property by virtue of which metals can be beaten into thin sheets is known as: A. Density B. Malleability C. Conductivity D. Ductility
Last Answer : ANSWER: B
Description : Silver is used for high precision electrical contacts in computer due to its property of ______. a) malleability b)conductivity c)ductility d)none
Last Answer : b)conductivity
Description : The property due to which a metal can be hammered into thin sheets without breaking is _______. a) malleability b)ductility c)tensile strength d)conductivity
Last Answer : a) malleability
Description : Property of material which allows it to be drawn out into wires is (A) Ductility. (B) Solder ability. (C) Super conductivity. (D) Malleability.
Last Answer : (A) Ductility.
Description : Hydrometer measures the specific gravity of liquids based on the principles of buoyancy. Pycnometer is used to measure the specific gravity of (A) Powder & granular solids (B) Liquids (C) Low melting point semi-solids (D) All 'a', 'b' & 'c
Last Answer : (D) All 'a', 'b' & 'c
Description : Which of the following characteristics is not typical of ionically bonded crystals? (a) Has no sharp melting point (b) Cleave into definite cleavage planes (c) Conducts when melted (d) Shatters when crystal is distorted
Last Answer : Ans:(a)
Description : Solids may be considered to be either crystalline noncrystalline. The basic difference between them is that a crystal, in contrast to a noncrystal: w) has a sharp melting point x) has an irregular array of atoms y) exhibits double refraction z) has a completely regular atomic or molecular structure
Last Answer : ANSWER: Z -- HAS A COMPLETELY REGULAR ATOMIC OR MOLECULAR STRUCTURE
Description : The property due to which the resistance of some metal or compound vanishes under certain conditions is (A) Semi conductivity. (B) Super conductivity. (C) Curie point. (D) Magnetostriction.
Last Answer : (B) Super conductivity.
Description : What terms describe a substance that has a low melting point and poor electrical conductivity?
Last Answer : covalent and molecular
Description : Addition of tungsten to steel imparts (A) Magnetic properties (B) Cutting hardness (C) Corrosion resistance (D) Ductility
Last Answer : (B) Cutting hardness
Description : Steels with high carbon equivalent have poor Weldability, because in these steels during welding (A) Carbon and other alloying elements get oxidised from the weld pool (B) Excessive ferrite forms in the ... of carbon and other element occurs in the weld pool leading to poor properties of the weld
Last Answer : (C) Martensite forms in the heat affected zone leading to poor toughness/ductility of the weld
Description : Presence of nickel & chromium in steel does not raise its (A) Elastic limit (B) Machining properties (C) Ductility (D) Resilience Answer: Option A
Last Answer : Option A
Description : Pick up the correct statement from the following: (A) The distance of the eccentric axial load from the C.G. beyond which tension develops, is known as kern distance (B) In visco ... (C) An orthotropic material has different properties in three mutually perpendicular directions (D) All the above
Last Answer : (D) All the above
Description : Silicon crystal can be converted to p-type semi-conductor by doping with (A) Phosphorous (B) Nitrogen (C) Carbon (D) Boron
Last Answer : Option D
Description : __________ of a material results, when its strength is increased & ductility is decreased by heating at a relatively lower temperature after cold working. (A) Solid solution hardening (B) Screw dislocation (C) Strain ageing (D) Twinning
Last Answer : (C) Strain ageing
Description : The electrical conductivity of a __________ decreases with rise in temperature. (A) Metal/alloy (B) Semi-conductor (C) Dielectric (D) None of these
Last Answer : (A) Metal/alloy
Description : Pick out the wrong statement. (A) Lead can creep under its own weight at room temperature (B) The electrical conductivity of gold is considerably reduced by alloying additions due to ... metal (D) With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase
Last Answer : (C) Recrystallisation temperature decreases with decrease in strain in a cold worked metal
Description : With increase in temperature, the electrical conductivity of a __________ decreases. (A) Semi-conductor (B) Metal or alloy (C) Dielectric (D) None of these
Last Answer : (A) Semi-conductor
Description : With increase in temperature, the electrical conductivity of semiconductors (A) Increases (B) Decreases (C) Remain constant (D) Either (A) or (B), depends on the type of semi-conductor
Description : What is error due to imperfection in experimental technique?
Last Answer : What is error due to imperfection in experimental technique?
Description : Considered as the main source of an internal noise. A. Device imperfection B. Thermal agitation C. Temperature change D. Flicker
Last Answer : B. Thermal agitation
Description : Dark current in light detectors is caused by ∙ a. Thermally generated carriers in the diode ∙ b. The absence of light input ∙ c. Small leakage current ∙ d. Its imperfection
Last Answer : a. Thermally generated carriers in the diode
Description : Nylon-66 compared to nylon-6 has (A) Lower melting point (B) More abrasion resistant properties (C) Higher hardness (D) All (A), (B) and (C)
Last Answer : (C) Higher hardness
Description : Solid and liquid phases of a substance are in equilibrium at the (A) Critical temperature (B) Melting point (C) Freezing point (D) Both (B) and (C)
Last Answer : D) Both (B) and (C)
Description : Curie point is the temperature at which (1) Matter becomes radioactive (2) A metal loses magnetic properties (3) A metal loses conductivity (4) Transmutation of metal occurs
Last Answer : (2) A metal loses magnetic properties Explanation: In physics and materials science, the Curie temperature (TO, or Curie point, is the temperature at which a ferromagnetic or a ... in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
Description : Curie point is the temperature at which (1) Matter becomes radioactive (2) A metal loses magnetic properties. (3) A metal loses conductivity (4) Transmutation of metal occurs.
Last Answer : A metal loses magnetic properties.
Description : Why does the conductivity of a semi conductor change with the rise in temperature ?
Last Answer : When a semi conductor is heated more & more electrons get enough energy to jump across the forbidden energy gap from valence band to the conduction band, where they are free to conduct electricity. Thereby increasing the conductivity of a semi conductor.
Description : . With increase in temperature, the electrical conductivity of semiconductors (A) Increases (B) Decreases (C) Remain constant (D) Either (A) or (B), depends on the type of semi-conductor
Description : Conductivity of semi conductor is increased by: a) Decrease of temperature b) By keeping temperature constant c) Increase of temperature d) none of above
Last Answer : d) none of above
Description : High endurance limit of carburised machine parts is because of the fact that carburisation (A) Suppresses any stress concentration produced in the parts (B) Enhances the yield point of the material (C) Introduces a compressive layer on the surface (D) Produces a better surface finish
Last Answer : (C) Introduces a compressive layer on the surface
Description : The graphite in grey irons exists in the form of flakes which act as stress-raisers under tensile loading and consequently grey irons have relatively low tensile strength and ductility. Still grey iron is extensively used in engineering. Why ?
Last Answer : (a) Cheapness. (B) Low melting point and high fluidity making it suitable for castings of intricate shape. (c) Relatively good erosion and corrosion resistance. (d) High damping capacity, with respect to vibration. (e) Relatively good mechanical properties under compressive loading.
Description : How could you use the physical properties of melting and boiling point to identify a substance?
Last Answer : The melting point and boiling point of a pure substance are veryspecific numbers; knowing these allows you to narrow down thepossible identity of the substance.
Description : A zwitterion has which of the following properties (a) no net charge (b) a high melting point (c) soluble in water (d) all of these
Last Answer : all of these