CSS Solved EDS Past Papers 1994 to 2013 Compressed.pdf

diverge énly slightly ss they travel. Thus a laser beam of 1 fect ciemeler when thrown cn the su-face cf the

‘oon in 1982 spread on an a°e3 of 2 mies diameter. A beam of erdinary ight would have spread on an

area of 25000 miles diameter. ;

Gi) Alloy: An. alloy consists of two or more elements, at least one of which is a metal. is formed by

mixing the base metal with an alloying element or elements to give required degree of stength, maileabilily

‘and other properties. Alloys have many applications, from high strength and high-resistance steel to ight,

magnesium based alloys used in the construction of aircaf.

Ir. practice very few metals are used in the pure state. Metals are characterized by thelr density.

strength, thermal and electrical conductivity and malieabilty (the easeness by which metais can be shaped

into various structures). Sometimes there qualities are not according to the requirements. Sometimes

excracedinary strength, light weight anc resistence to chemical action is required. No single metal con fulfil

these requirements end thus alloys ace used which express combination of properties.

(v) Polymer: Polymers are composed of very large molecules formed by Sinking together many

smal, more simple units called monomers. The process of inking together the monomers and making