MCQ
681. Silicon in cast iron-
Incrouse hardness and brittleness
Maker the iron write and hard
Aids fusibility and fluidity
Makes the iron soft and easily Machinable
682. In the lower part of the blast furnace (Zone of fusion) the temperature is—
800-1000°C
1500-1700°C
400-700°C
1200-1300°C
683. Taps, dies and drills contain carbon-
below 0.5%
below 1%
above 1%
above 2.2%
684. Drop forging dies contain carbon of the order of --
0.1 to 0.2%
0.25 0.5%
0.6 to 0.7%
0.7 to 0.9%
685. Muntz metal (yellow brass) contains—
70% copper and 30% zinc
60% copper and 40% zinc
60% copper and 30% zinc
60.45% copper, 35.2% zinc and 5.35% nickel
686. Shock resistance of steel in increased by adding--
Nickel
Chromium
Nickel and chromium
Sulphur load and phosphorus
687. Iron carbon alloy containing carbon --4.3% carbon are known as hyper-eutectic cast Irons.
usual to
more than
less than
none of them
688. What is used as joining medium in brazing operation?
Copper-Zinc alloy
Lead-Tin alloy
Nickel-Silver alloy
All of the above
689. The material commonly used for machine tool bodies is-.
mild steel
brass
aluminium
cast iron
690. Brass is an alloy of--
Copper and Tin
Copper, Tin and Phosphorous
Zinc, Copper, Tin and Phosphorous
Zinc and Copper
691. Which of the following impunity in the cast iron promoter graphite module formation and increase the fluidity of the molten metal?
Sulphur
Manganese
Phorphorus
Silicon
692. The carbon in the pig iror varier from-
0.1 to 0.5%
1 to 5 %
0.5 to 15%
5 to 10%
693. Cast-iron is--materia.
Ductile
Malleable
Brittle
Tough
694. Copper when alloyed with Zinc is known as –
Brass
gun metal
bronge
nicrome
695. The austenitic stainless steel centrums-
18% chromium and 8% nickel
8% chromium and 18% nickel
14% nickel and 0.35% carbon
14% nickel and 0.35% carbon
696. A steel with carbon is --known as hyper- eutectoid steel--
0.87%
below 0.8%
above 0.8%
None of them
697. Which is binding material?
Sand
Cement
Khoa
Rod
698. The usual composition of a soldering alloy is--
tin and lead
Tin, lead and small percentage of antimony
tin, lead and silver
tin and copper
699. Nodular cast iron is produced by adding the molten cast iron-
Nickel
Copper
Chromium
Magnesium
700. The pointer of an indicating instrument is generally made of—
copper
silver
aluminium
soft steel