529. Main alloying element in Elinvar used in precision instruments, hair springs for watches etc. is
A. Chromium
B. Nickel
C. Zinc
D. Aluminium
✅ The correct answer is option B.
531. Overheating of satellites during re-entry to earth is controlled by
A. Thick insulation
B. Ceramic lining
C. Cooling by flow of air over the surface
D. None of these
✅ The correct answer is option C.
533. The most important consideration in value engineering is the
A. Profit maximisation
B. Customer satisfaction
C. Cost reduction
D. Process improvement
✅ The correct answer is option B.
497. Which of the following metals can be extracted from its ore by both pyrometallur-gical as well as hydrometallurgical methods ?
A. Copper
B. Zinc
C. Both A & B
D. Neither A nor B
✅ The correct answer is option C.
499. Which of the following metals can not be extracted by pyrometallurgical process from its sulphide ore?
A. Copper
B. Mercury
C. Lead
D. None of these
✅ The correct answer is option B.
502. Brass parts with high residual tensile stress at the surface are susceptible to season cracking (i.e. spontaneous cracking occuring on exposure to atmospheric corrosion), if its zinc percentage is more than
A. 5
B. 10
C. 20
D. 35
✅ The correct answer is option C.
505. The noble metals
A. Are exemplified by Na, K and Li
B. Do not resist corrosion very strongly
C. Are the lowermost in the electro-chemical series of metals
D. None of these
✅ The correct answer is option C.
508. Monazite deposits constitute an important source for the following metal.
A. Thorium
B. Titanium
C. Molybdenum
D. None of the above
✅ The correct answer is option A.
511. Large diameter shafts are manufactured by
A. Hot rolling
B. Cold drawing
C. Casting and turning to size
D. Forging and turning to size
✅ The correct answer is option D.
514. The ultimate strength in tension for steel is __________ times the ultimate strength in shear.
A. 0.5
B. 0.9
C. 1.5
D. 2.5
✅ The correct answer is option C.