Materials and Construction

A. The toughness of a material decreases, when it is heated
B. Crane hooks are normally made of wrought iron
C. Cold working of a metal decreases its fatigue strength
D. The temperature at which new grains are formed in a metal is known as the recrystallisation
temperature

A. Pure rubber is as useless as pure gold as a material of construction
B. Thermal conductivity of aluminium is higher than that of copper; hence it is increasingly used for utensil making
C. Copper has poor weldability
D. Reinforced plastics are made from both thermoplastic as well as thermosetting plastics

A. Wrought iron contains about 0.02% carbon
B. Wrought iron cannot be easily forged and welded
C. The chilled cast iron does not contain graphite
D. Spheroidal grey cast iron contains graphite flakes

A. Stainless steel is nothing but chromium coated steel
B. Hardening of a soft metal can be done by alloying it with another metal or non-metal
C. Plastic deformation of a material is its temporary distortion under the action of applied stress
D. Rusting of iron is not electrochemical in nature

A. Hardening makes the steel more brittle
B. High alloy steels contain more than 50% alloying element
C. 18/8 stainless steel is a magnetic steel
D. Both B. and C.

A. Alloys are harder than their component elements
B. Presence of silicon in steel decreases its electrical resistance
C. Karbate is an acid resistant material of construction
D. Nichrome, a steel alloyed with 10% Ni and 20% Cr can be used upto a temperature of 1100°C

A. Tin can be readily and very easily drawn into very fine wire
B. Tin can be severely cold worked without the necessity of annealing due to its low recrystallisation temperature
C. Tin exists in two allotropic forms
D. The predominant use of tin is in the form of coating for steel & copper alloys

A. Bronze is an alloy of copper & tin
B. Brass is an alloy of copper & zinc
C. The alloy named ‘German silver’ does not contain any silver
D. The ability of a material to fracture without appreciable deformation is called its ductility

A. 1 to 15
B. 1 to 8
C. 1 to10
D. 0 to 10

A. Cork
B. Glass
C. Graphite
D. Rubber