Area of the section of the heat flow path, perpendicular to the direction of heat flow. When a homogeneous mixture of two (or more) atomic forms exists in solid state, it is known as solid solution. CCP (cubic dosed packed) structure-Copper. What is a converter reactor ? Ferrite is a magnetic iron rock. 28. but little variation of creep properties with carbon content. What is the effect of friction on flow of steam through a nozzle ? What is caustic embrittlement ? 91. What is big advantage of fast breeder reactor ? If steel is heated above the A critical temperature to dissolve all the carbides, and then cooled, suitable cooling through the cooling range will produce the desired size and distribution of carbides in the ferrite, imparting different properties. What is fuel ratio ? 75. What are the major effects of alloying elements? Explain the formation of microstructures of pearlite, bainite and martensite in steel. On ultimate analysis. Pingback: Interview Questions On Strength of Materials | Questions Asked in Mechanical Engineering Interview | Mechanical Engineering Blog, Your email address will not be published. What is burnt-out point ? 142. 79. are independent of mass. What is the percentage of carbon in cast iron ? 4. Perfection of material conditions is possible at lower sizes and as size increases, it is not possible to attain uniform structure of the material. Why ? Alloys are produced by melting or sintering two ore more metals, or metals and a non-metal, together. To which countries these standards belong ? Whiskers are very small crystals which are virtually free from imperfections and dislocations. It decreases weldability. What is the difference between scavenging and supercharging ? It is a solid formed by combination of metallic and non-metallic elements. 23. c. High latent heat of vaporization. Peritectic. It is soft, ductile and relatively weak. (v) Reliability and safety—Endurance limit and yield point. Silicon in excess of 2.5% causes brittleness, and amounts higher than 5% make the steel non-malleable. The gas flows thorugh bed without disturbing particles significantly but gas velocity is high enough to support the total weight of bed (fluidisation). View factor is dependent upon geometry of the two surfaces exchanging radiation. What is pitting ? 114. 105. Save my name, email, and website in this browser for the next time I comment. A refrigent should have . Integrated gasification combined cycle systems. (iv) wear resistance Iso-octane permits highest compression without causing knocking. Steam Boilers, Engines, Nozzles and Turbines PART 1 . A stress in excess of elastic limit, with no external force to oppose it, will relieve itself by plastic deformation until it reaches the value of the yield stress. A peritectic transformation involves a reaction between a solid and liquid that form a different and new solid phase. Under what conditions it approaches isobaric, isothermal, and isometric process ? In gas turbines, 70% of the output of gas turbine is consumed by compressor. Out of electric heater and heat pump, which is economical in operation ? 80. Fatigue is the reduced tendency of material to offer resistance to applied stress under repeated or fluctuating loading condition. Temperature increases and pressure decreases. .Normal carburising/nitriding treatments increase volume due to phase transformation at Surface and introduce residual compressive surface stress and thus increase the fatigue strength. Embrittlement attack is usually intergranular in metals, i.e. It is least when compression process approaches isothermal. 43. How with alloying of steel it is possible to a achieve properties which can not be achieved with heat treatment ? Self sustained, continuing, sequence of fission reactions in a controlled manner is fission chain reaction. What is the difference between heat capacity and specific heat of a material ? Throttling process. 164. What is the difference between column and strut ? 74. 147. 10. 200, in case of throttling enthalpy constant ok, but incase of isentropic also known reversible adiabatic process how heat transfer will occur. Modulus of resilience is the maximum strain energy stored in a material per unit volume and modulus of rigidity is the ratio of shearing stress to the shearing strain within the elastic limit. How the analyses and calorific values of fuels can be reported ? (a) Zero or low radioactivity material is dispersed or stored without elaborate shielding. A cable attached to the supports and carrying its own weight. 162. Silicon increases the electrical resistivity of steel and decreases hysteresis losses. Why an increase in area is required to produce an increase of velocity in case of supersonic flow ? 189. Which reactor uses primary coolant as fluoride salts of lithium, beryllium, thorium and uranium ? What is the principle of mechanical refrigeration ? Mention two types of dislocations. For conduction of heat, the instantaneous rate of heat flow is product of three factors. Which parameter remains constant in a throttling process ? A polytropic process is one that follows the equation pun = constant (index n may have values from – oc to + oo. Ratio of their thickness = (Prandtl number)-1/3. It satisfies equation of state and its specific heats are constant. 19. Thermal n is high for weak mixture and it decreases as mixture strength becomes rich. Why iso-octane is chosen as reference fuel for S.I. Proximity analysis of coal provides data for a first, general assessment of a coal’s quality and type. MECHANICAL ENGINEERING Interview Questions and Answers PDF free download, 300 MECHANICAL ENGINEERING Interview Questions and Answers, 400 MECHANICAL ENGINEERING Interview Questions and Answers, 500 MECHANICAL ENGINEERING Interview Questions and Answers, 600 MECHANICAL ENGINEERING Interview Questions and Answers. What is allotrope ? What is view factor ? A state in which a liquid alloy (or metal) coexists with its crystals is a two-phase system. The property of a material which enable it to resist fracture due to high impact loads is known as, a. 87. Which reactor produces more fissionable material than it consumes ? These are associated with change of section and/or weld undercut, where tubes are expanded or welded into headers. In which reversible process no work is done ? These desirable effects partially compensate for the tendency of silicon to lower the creep properties of steel. The lower temperature form is known as “alpha”-iron and the higher temperature form as “delta”-iron. Heat pump. The moisture content of the bulk as sampled is referred to as total moisture, and that of the air dried sample is called inherent moisture. What are killed steels and what for these are used ? Chromium. 123. Why large boilers are water tube type ? List two effects of manganese in plain carbon steels. If percentage elongation of a material is more than 200%, it is classed as ? 61. 31. n-heptane and ISO-octane. Why the electric motor of a fan with backward curved blades is never got overloaded under any condition ? Low melting point and high fluidity making it suitable for castings of intricate shape. The specific heat of a material is the ratio of the amount of heat transferred to raise unit mass of a material 1 degree in temperature to that required to raise unit mass of water 1 degree of temperature at some specified temperature. Execessive hydrogen results in the formation of small fissures often described as hairline cracks or flakes in the steel. Failure may occur due to following reasons : Explain the difference between AFBC, BFBC, PFBC and PCFB in regard to fluidised bed technologies. At slightly higher velocity excess gas passes through the bed as bubbles (fluidised bed) and gives the bed the appearance of a boiling liquid. Compressors, Gas Turbines and Jet Engines PART 1 . Under what condition the work done in reciprocating compressor will be least ?