Out of the following, the best material capable of withstanding shock & vibration without the danger of cracking is:
A. Malleable iron
B. Grey cast iron
C. Chilled cast iron
D. White cast iron
The most serious manufacturing defect from fracture toughness point of view is:
A. Surface roughness
B. Pores
C. Spherical inclusion
D. Crack
______ has the highest melting point out of the following:
A. Tungsten
B. Zirconium
C. Molybdenum
D. Tantalum
Air-petrol ratio for maximum power generation in spark ignition engine is about:
A. 6 : 1
B. 12 : 1
C. 18 : 1
D. 24 : 1
Galvanic corrosion cannot be prevented by:
A. Cathodic protection
B. Anodic protection
C. Usage of largest possible anodic area
D. Any one of these
Fire in fuel gas pipelines is extinguished most effectively by:
A. Spraying water
B. Blanketting the area with nitrogen atmosphere
C. Fire fighting foam
D. None of these
Fibrous fracture is normally encountered in the ____ materials:
A. Hard
B. Elastic
C. Ductile
D. Brittle
The elastic strain energy of a unit length of an edge dislocation as compared to that of a screw dislocation is:
A. More
B. Equal
C. Less
D. Double
Addition of silicon to cast iron:
A. Promotes graphite module formation
B. Improves its ductility
C. Does not promote graphite flakes formation
D. Increases the fluidity of molten metal
______ is used as a material of construction for the blade of power saw:
A. Wrought iron
B. Stainless steel
C. Mild steel
D. High speed steel
