mechanical engineering MCQs – Page 54

Practise multiple-choice questions from mechanical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

2651. Slow plastic defomiation of metals under a constant stress is known as________________?
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A. creep

B. endurance

C. non-plastic deformation

D. plastic deformation

E. fatigue

2652. Cold rolled steel sheets contain carbon of the following order___________________?
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A. 0.20%

B. 0.60%

C. 0.80%

D. 0.1%

E. 0.40%

2653. Which of the following is used for bearing liner_______________?
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A. gun metal

B. bell metal

C. bronze

D. babbit metal

E. brass

2654. Depth of hardness of steel is increased by addition of_________________?
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A. chromium

B. ell of the above

C. nickel

D. tungsten

E. vanadium

2655. Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio _____________________?
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A. 50 : 20 : 10 : 20

B. 40 : 30 : 20 : 10

C. 50 : 10 : 20 : 20

D. 30 : 20 : 30 : 20

E. 50 : 20 : 20 : 10
2656. Foundry crucible is made of_________________?
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A. mild steel

B. graphite

C. cast iron

D. lead

E. german silver

2657. Argentite is the principal ore or raw material for _________________?
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A. silver

B. tin

C. aluminium

D. zinc

E. lead

2658. Neutral solution is one which has pH value__________________?
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A. none of the above

B. greater than 7

C. pH value has nothing to do with neutral solution

D. less than 7

E. equal to 7
2659. Pick up the wrong statement?
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A. manganese in steel induces hardness

B. nickel and chromium in steel help in raising the elastic limit and improve the resilience and ductility

C. sulphur, phosphorous and lead improve machining properties of steel

D. tungsten in steels improves magnetic properties and hardenability

E. aluminium in steel results in excessive grain growth
2660. Nickel in steel___________________?
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A. improves wear resistance, cutting ability and toughness

B. improves cutting ability and reduces hardenability

C. gives ductility, toughness, tensile strength and anticorrosion properties

D. refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties

E. none of the above

2661. The metallic structure of mild steel is_________________?
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A. orthorhombic crystal

B. face centred cubic

C. body centred cubic

D. hexagonal close packed

E. cubic structure

2662. Maximum percentage of carbon in ferrite is___________________?
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A. 0.25%

B. 0.06%

C. 0.10%

D. 0.8%.

E. 0.025%
2663. Hardness of lower bainite (tempered martensite) is about________________?
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A. RC 57

B. RC 48

C. RC 32

D. RC 65

E. RC 80

2664. Annealing of white cast iron results in production of_________________?
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A. grey iron

B. spheroidal iron

C. none of the above

D. nodular iron

E. malleable iron
2665. Which of the following elements does not impart hardness to steel__________________?
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A. copper

B. chromium

C. silicon

D. none of the above

E. nickel

2666. Heavy duty leaf and coil spring* contain carbon of the following order ________________?
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A. 1.0%

B. 0.50%

C. 1.5%.

D. 0.20%

E. 0.80%

2667. Which of the following has highest specific strength of all structural materials__________________?
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A. chromium alloys

B. none of the above

C. titanium alloys

D. magnesium alloys

E. magnetic steel alloys

2668. An engineers hammer is made of___________________?
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A. forged steel

B. high carbon steel

C. cast iron

D. mild steel

E. H.S.S

2669. Pearlite is a combination of___________________?
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A. ferrite and cementite

B. cementite and gamma iron

C. pearlite and ferrite

D. ferrite and iron graphite

E. ferrite and austenite

2670. Malleable cast iron _________________?
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A. contains l.7 to 3.5% carbon in free state and is obtained by the slow cooling of molten cast iron

B. none of the above

C. is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable

D. is produced by small additions of magnesium (or cerium) in the ladle. Graphite is in the nodular or spheroidal form and is well dispersed throughout the material

E. is produced by annealing process. It is soft, tough, and easily machined metal
2671. In mottled cast iron, carbon is available in__________________?
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A. nodular form

B. flat form

C. combined form

D. free form

E. partly in free and partly in combined state
2672. Weld decay is the phenomenon found with _________________?
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A. wrought iron

B. non-ferrous materials

C. mild steel

D. cast iron

E. stainless steel
2673. The ultimate tensile strength of low carbon steel by working at a high strain rate will_________________?
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A. increase

B. decrease

C. first decrease and then increase

D. first increase and then decrease

E. remain constant

2674. Addition of lead and bismuth to aluminium results in_________________?
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A. improvement of casting characteristics

B. none of the above

C. improving machinability

D. improvement of corrosion resistance

E. one of the best known age and precipitation-hardening systems

2675. Cast iron is characterised by minimum of following %age of carbon_________________?
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A. 2%

B. 1.30%

C. 6.3%.

D. 0.20%

E. 0.80%

2676. Drop forging dies contain carbon of the order of_________________?
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A. 0.6 to 0.7%

B. 0.25 to 0.5%

C. 0.7 to 0.9%

D. 0.1 to 0.2%

E. 1.0 to 1.2%.

2677. Delta iron occurs at temperature of_______________?
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A. above melting point

B. between 1400C and 1539C

C. between 910C and 1400C

D. room temperature

E. none of the above

2678. The machinability of steel is increased by___________________?
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A. silicon and sulphur

B. none of the above

C. phosphorous, lead and sulphur

D. sulphur, graphite and aluminium

E. phosphorous and aluminium

2679. If a refractory contains high content of silicon, it means refractory is__________________?
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A. basic

B. neutral

C. acidic

D. none of the above

E. brittle

2680. Corrosion resistance of steel is increased by addition of________________?
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A. zinc

B. sulphur, phosphorus, lead

C. chromium and nickel

D. vanadium, aluminium

E. tungsten, molybdenum, vanadium, chromium

2681. Tungsten in steel________________?
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A. improves wear resistance, cutting ability and toughness

B. refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties

C. improves cutting ability and reduces hardenability

D. gives ductility, toughness, tensile strength and anticorrosion properties

E. raises its melting point

2682. White cast iron__________________?
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A. is produced by annealing process. It is soft, tough and easily machined metal

B. none of the above

C. contains 1.7 to 3.5% carbon in free state and is obtained by the slow cooling of molten cast iron

D. is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable

E. is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material

2683. The transistor is made of___________________?
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A. germanium

B. german silver

C. copper

D. silver

E. gold

2684. Tungsten in high speed steel provides________________?
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A. cold hardness

B. toughness

C. wear resistance

D. hot hardness

E. sharp cutting edge

2685. The tensile strength of wrought iron is maximum _________________?
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A. along the lines of slag distribution

B. uniform in all directions

C. none of the above

D. perpendicular to lines of slag distribution

E. unpredictable

2686. Austenite rs a combination of_________________?
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A. ferrite and iron graphite

B. pearlite and ferrite

C. ferrite and austenite

D. ferrite and cementite

E. cementite and gamma iron
2687. Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio_________________?
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A. 60:40:00

B. 30 : 70

C. 50:50:00

D. 40 : 60

E. 70:30:00

2688. Nodular iron has____________________?
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A. all of the above

B. high maehinability

C. low melting point

D. good fluidity

E. high tensile strength

2689. Structural steel contains following principal alloying elements__________________?
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A. zinc, sulphur, and chromium

B. nickel, chromium and manganese

C. none of the above

D. tungsten, molybdenum and phosphorous

E. lead, tin, aluminium

2690. Free cutting steels_____________________?
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A. contain carbon in free form

B. require least cutting force

C. are used where ease in machining is the criterion

D. can be cut freely even under adverse conditions

E. do not exist

2691. Which is false statement about annealing. Annealing is done to________________?
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A. harden steel slightly

B. permit further cold working

C. soften material

D. relieve stresses

E. improve machining characteristic

2692. The usual composition of a soldering alloy is__________________?
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A. tin and lead

B. tin, lead and silver

C. tin, copper and lead

D. tin, lead and small percentage of antimony

E. tin and copper

2693. Gun metal contains__________________?
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A. 85-92% copper and rest tin with little lead and nickel

B. 85-92% copper and rest zinc

C. 90% copper and 10% tin

D. 70-78% copper and rest tin

E. 70% copper and 30% zinc

2694. A specimen of aluminium metal when observed under microscope shows __________________?
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A. a complex cubic structure

B. F.C.C. crystal structure

C. B.C.C. crystalline structure

D. H.C.P. structure

E. orthorhombic crystalline structure

2695. Pig iron is the name given to________________?
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A. product of blast furnace made by reduction of iron ore

B. iron scrap

C. raw material for blast furnace

D. iron in molten form in the ladles

E. iron containing huge quantities of carbon

2696. Grey cast iron_____________________?
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A. is also known as chilled cast iron am is obtained by cooling rapidly. It i: almost unmachinable

B. is produced by small additions o magnesium (or cerium) in the ladle Graphite is in nodular or spheroida form and is well dispersed throughout the material

C. contains 1.7 to 3.5% carbon in free state and is obtained by the slow cooling of molten cast iron

D. is produced by annealing process. I is soft, tough and easily machinec metal

E. none of the above is true

2697. Brass contains___________________?
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A. 70-75% copper and rest tin

B. 90% copper and 10% tin

C. 85-92% copper and rest tin with little lead and nickel

D. 70% copper and 30% zinc

E. 70% copper and 30% tin

2698. Basic constituents of Monel metal are _________________?
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A. zinc, tin, lead

B. nickel, lead and tin

C. nickel, molybdenum

D. nickel, copper

E. none of the above

2699. Corrundum contains more than 95% _____________________?
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A. steel

B. A1203

C. MgO

D. german silver

E. Si02

2700. Bronze contains_____________________?
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A. 85-92% copper and rest tin with little lead and nickel

B. 90% copper and 10% tin

C. 70-75% copper and rest tin

D. 70% copper and 30% zinc

E. 90% copper and 10% zinc