386. With increase in impurities in metals, their corrosion resistances
A. Increase
B. Decrease
C. Remain same
D. May increase or decrease ; depending on the type of metal
✅ The correct answer is option B.
389. Which of the following has the least value of ultimate tensile strength (UTS)?
A. Medium carbon steel
B. High carbon steel
C. Cast iron
D. Wrought iron
✅ The correct answer is option B.
392. Solution loss reaction occurs
A. In the blast furnace shaft
B. During pretreatment of hot metal
C. In the L.D. process
D. During deoxidation in the ladle
✅ The correct answer is option A.
394. Increasing sulphur content in pig iron tends to make it
A. Soft
B. Hard
C. Tough
D. Ductile & malleable
✅ The correct answer is option B.
396. Absolute zero, pressure will occur, when the molecular momentum of the system becomes zero. A liquid will cease to exist as liquid at
A. High vacuum
B. Zero pressure
C. 0°K
D. Earth
✅ The correct answer is option B.
398. For efficient performance of a blast furnace, the extent of reduction of Wustite (FeO) should be
A. 100% indirect reduction
B. 100% direct reduction
C. 50-60% indirect reduction
D. 30-40% indirect reduction
✅ The correct answer is option C.
400. Fatigue strength of a material can not be increased by
A. Cold working
B. Hot working
C. Shot peening
D. Any of these
✅ The correct answer is option B.
402. The ratio of the shear stress to the principal stress on a principal plane is
A. 0
B. 1
C. 1/2
D. 1/3
✅ The correct answer is option A.
404. __________ has the highest melting point out of the following.
A. Tungsten
B. Zirconium
C. Molybdenum
D. Tantalum
✅ The correct answer is option A.
406. Needles are produced by
A. Forging
B. Swaging
C. Extrusion
D. Machining
✅ The correct answer is option B.