431. When an isolated thermodynamic system executes a process ___________________?
A. Heat transfer takes place
B. Work is done
C. Mass flow occurs across the boundary of the system
D. No chemical reaction takes place within the system

432. The main constituent of bones is ______________________?
A. CaCO3
B. Ca3(PO4)2
C. CaF2
D. CaCl2

433. Which of the following alloying elements is present in maximum percentage in high speed steel ?
A. Molybdenum
B. Tungsten
C. Chromium
D. Vanadium

434. Baffles provided on the shell side of a shell and tube heat exchanger are meant for _____________________?
A. Improving heat transfer
B. Providing support for the tubes
C. Both A & B
D. Preventing the fouling of tubes & stagnation of shell side fluid

435. While the bin cards are used in the effective stores management, the queuing theory is associated with the _______________ time ?
A. Waiting
B. Inspection
C. Idle
D. Tool replacement

436. ______________________ iron is produced by the annealing of white cast iron?
A. Malleable
B. Ductile
C. Nodular
D. Grey

437. With increase in impurities in metals, their corrosion resistances____________________?
A. Remain same
B. Decrease
C. Increase
D. May increase or decrease; depending on the type of metal

438. In the blast furnace, incorporation of water vapour in the blast gives the following effect ?
A. Increases the reducing potential of the gas
B. No significant change occurs
C. Increases the flame temperature
D. Increases the hydrogen content in the metal

439. The product out from a cupola is called ____________________?
A. Pig iron
B. Wrought iron
C. Cast iron
D. None of these

440. The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the ‘Curie temperature’. Its value for cobalt is ______________ °C?
A. 1359
B. 1127
C. 768
D. 1480

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