DVC Three molecules of type A, four of type B, three of type C and five of type D are to be linked together to form a chain molecu
such chain molecule Is ABDDABADCBDCCDB.
How many such chain molecules can be formed in such a way that the molecules on either ends are type D? (Answer]

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.

Draw the engineering stress-strain curve for (a) bcc; (b) fcc metals and mark important points.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.