Ans If a material exhibits same mechanical properties regardless of loading direction, it is isotropic eg., homogeneous cast materials. Materials lacking this property are anisotropic

2    What are orthotropic materials

It is a special class of anisotropic materials which can be described by giving their properties in three perpendicular direction et wood composites

3    A plain carbon steel has BHN of 180 What are values of R^{c, VHN and ultimate strength?}

^{Ans Rc-RHN/10  18,VHN BHN 180}

^{4    What properties need to be considered for applications calling for following requirement:}

^irigdity

^{strength for no plastic deformation under static load}

^{wear resistance}

^{reliability and safety}

^{Ans Rigidity- elastic modules and yield strength}

^{Strength for no plastic deformation under static loading-yield point}

^{Wear resistance-Hardness}

^{Reliability and safety-Endurance limit and yield point}

^{5     Explain the effects of alloying chromium and nickel in stainless steel.}

^{Addition of nickel and chromium increases the tensile strength and increase in resistance to corrosion takes place.}

^{6    Mention two types of dislocation'}

^{Dislocation refers to a break in the continuity of the lattice. In edge dislocation, one place of atoms gets squeezed out.In screw dislocation the lattice atoms move from their regular ideal positions.}

^{7    What are the principal constituents of brass?}

^{Principal constituents of brass are copper and zinc}

^{8 what is curie point?}

^{Curie point is te temperature at which ferromagnetic materials can no longer be magnetized by outside forces}

^{9 Specific strength of materials is very high when they are in fiber size but lower when they are in bar form-Why?}

^{Crystal structure has ordered, repeating arrangement of atoms, fibers are liable to maintain this and thus have high specific strength. As size increases, the condition of ordered and repeating arrangements cant be guaranteed because of several types of defects and dislocations and thus the specific strength gets lower}

^{10    what is the percentage of carbon in cast iron?}

^2.5%

^{11     Which element is added in steel to increase resistance to corrosion?}

^Chromium

^{12     whether individual component material retain their characteristics or not} 

^Yes

^{13    An elastomer is a polymer when its percentage elongation rate is}

^{Greater than 100%}

^{14    If % elongation of material is more tha  200% it is classed as}

^Rubber

^{15    Why is it that the maximum value which the residual stress can reach is the elastic limit of the material?}

^{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}