mechanical engineering mcqs to prepare for nts, kppsc, fpsc, ppsc and more

mechanical engineering Mcqs

1. compressors gas turbines and jet engines 2. theory of machines 3. nuclear power plants 4. engineering materials 5. strength of materials mechanical engineering 6. thermodynamics 7. heat transfer 8. i c engines 9. steam boilers engines nozzles and turbines 10. engineering mechanics 11. fluid mechanics mechanical engineering 12. production technology 13. machine design 14. hydraulic machines 15. workshop technology 16. refrigeration and air conditioning

1751. Depth of hardness of steel is increased by addition of_________________?
0

A. vanadium

B. nickel

C. tungsten

D. ell of the above

E. chromium

1752. The hardness of steel increases if it contains____________________?
0

A. pearlite

B. austenite

C. all of the above

D. cementite

E. martensite

1753. Basic solution is one which has pH value___________________?
0

A. none of the above

B. greater than 7

C. less than 7

D. pH value has nothing to do with basic solution

E. equal to 7

1754. A bucket of water is hanging from a spring balance. An iron piece is suspended into water without touching sides of bucket from another support. The spring balance reading will_________________?
0

A. increase/decrease depending on depth of immersion

B. decrease

C. increase

D. remain same

E. unpredictable

1755. In mottled cast iron, carbon is available in__________________?
0

A. flat form

B. nodular form

C. partly in free and partly in combined state

D. free form

E. combined form

1756. The atmospheric pressure with rise in altitude decreases__________________?
0

A. unpredictable

B. linearly

C. first slowly and then steeply

D. none of the above

E. first steeply and then gradually

1757. In malleable iron, carbon is present in the form of___________________?
0

A. free carbon

B. flakes

C. cementite

D. spheroids

E. nodular aggregates of graphite

1758. A material is known as allotropic or polymorphic if it __________________?
0

A. has its atoms distributed in a random pattern

B. exists in several crystal forms at different temperatures

C. has a fixed structure under all conditions

D. responds to heat treatment

E. none of the above

1759. An example of amorphous material is____________?
0

A. zinc

B. silver

C. brass

D. glass

E. lead

1760. Sulphur in steel________________?
0

A. reduces the grain size

B. lowers the toughness and transverse ductility

C. acts as deoxidiser

D. decreases tensile strength and hardness

E. increases hardness

1761. For measuring flow by a venturimeter, if should be installed in __________________?
0

A. in any direction and in any location

B. vertical line

C. horizontal line

D. inclined line with flow downward

E. inclined line with upward flow

1762. Cobalt in steel __________________?
0

A. improves cutting ability and reduce hardenability

B. refines grain size and produces les tendency to carburisation, improve corrosion and heat resistant proper ties

C. improves wear resistance, cuttinability and toughness

D. none of the above

E. gives ductility, toughness, tensile strength and anti corrosion property:

1763. The composition of silver solder is ___________________?
0

A. silver, lead, tin

B. silver, copper, zinc

C. silver, tin, nickel

D. silver, lead, zinc

E. silver, copper, aluminium

1764. If w is the specific weight of liquid and k the depth of any point from the surface, then pressure intensity at that point will be________________?
0

A. wh

B. h/w

C. h

D. h/wh

E. w/h

1765. The loss of strength in compression with simultaneous gain in strength in tension due to overloading is known as________________?
0

A. hysteresis

B. creep

C. Boeschinger effect

D. inelasticity

E. visco elasticity

1766. The capillary rise at 20C in a clean glass tube of 1 mm bore containing water is approximately____________________?
0

A. 20 mm

B. 1 mm

C. 10 mm

D. 5 mm

E. 30 mm

1767. Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio _____________________?
0

A. 50 : 20 : 20 : 10

B. 40 : 30 : 20 : 10

C. 30 : 20 : 30 : 20

D. 50 : 20 : 10 : 20

E. 50 : 10 : 20 : 20

1768. DuraJomin contains___________________?
0

A. 94% aluminium and 6% tin

B. 90% magnesium and 9% aluminium with some copper

C. 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe

D. 10% aluminium and 90% copper

E. 92.5% aluminium, 40% copper, 2% nickel, and 1.5% Mg

1769. If a refractory contains high content of silicon, it means refractory is__________________?
0

A. acidic

B. brittle

C. neutral

D. basic

E. none of the above

1770. Operation of McLeod gauge used for low pressure measurement is based on the principle of_________________?
0

A. Boyles law

B. McLeods law

C. Pascals law

D. Charles law

E. gas law

1771. A liquid compressed in cylinder has a volume of 0.04 m3 at 50 kg/cm2 and a volume of 0.039 m3 at 150 kg/cm2. The bulk modulus of elasticity of liquid is___________________?
0

A. 40 x 105 kg/cm2

B. 40 x 106 kg/cm2

C. 400 kg/cm2

D. 4000 kg/cm2

E. none of the above

1772. A square surface 3 m x 3 m lies in a vertical line in water pipe its upper edge at water surface. The hydrostatic force on square surface is____________________?
0

A. 30,000 kg

B. 13,500 kg

C. 27,000 kg

D. 18,000 kg

E. 9,000 kg

1773. Tungsten in high speed steel provides________________?
0

A. sharp cutting edge

B. cold hardness

C. wear resistance

D. toughness

E. hot hardness

1774. Amorphous material is one___________________?
0

A. in which atoms align themselves in a geometric pattern upon solidification

B. which is not attacked by phosphorous

C. which emits fumes on melting

D. in which there is no definite atomic structure and atoms exist in a random pattern just as in a liquid

E. none of the above

1775. The center of pressure of a surface subjected to fluid pressure is the point_______________?
0

A. where pressure equivalent to hydraulic thrust will act

B. on the surface at which resultant pres-sure acts

C. at which all hydraulic forces meet

D. similar to metacentre

E. on the surface at which gravitational force acis

1776. Which of the following elements does not impart hardness to steel__________________?
0

A. silicon

B. chromium

C. none of the above

D. nickel

E. copper

1777. In order to increase sensitivity of U-tube manometer, one leg is usually inclined by angle 9. Sensitivity of inclined tube to sensitivity of U-tube is equal to________________?
0

A. tan 9

B. cos 9

C. sin 9

D. cas 9

E. sin 9

1778. Hardness of lower bainite (tempered martensite) is about________________?
0

A. RC 65

B. RC 32

C. RC 57

D. RC 48

E. RC 80

1779. White cast iron contains carbon in the form of__________________?
0

A. free carbon

B. white carbon

C. graphite

D. cementite

E. ferrite

1780. Maximum percentage of carbon in ferrite is___________________?
0

A. 0.06%

B. 0.8%.

C. 0.25%

D. 0.025%

E. 0.10%

1781. Specific weight of water in S.I. units is equal to ________________?
0

A. 9.81 N/m3

B. 10000 N/m3

C. 9.81 xlO6N/m3

D. 1000 N/m3

E. 9.81 xlO3 N/m3

1782. The units of dynamic or absolute viscosity are__________________?
0

A. newton-sec per meter

B. metres2 per sec

C. none of the above

D. kg sec/meter

E. newton-sec2 per meter

1783. The surface hardness of the following order is achieved by nitriding operation__________________?
0

A. 1000 to 1100 VPN

B. 600 VPN

C. 1500 VPN

D. 2000 VPN

E. 250 VPN

1784. Paramagnetic alpha iron changes to gamma iron at_______________?
0

A. 1440C

B. 770C

C. 910C

D. 1539C

E. none of the above

1785. Pearlite is a combination of___________________?
0

A. ferrite and cementite

B. cementite and gamma iron

C. pearlite and ferrite

D. ferrite and austenite

E. ferrite and iron graphite

1786. Brass (alloy of copper and zinc) is an example of__________________?
0

A. interstitial solid solution

B. none of the above

C. intermetallic compounds

D. all of the above

E. substitutional solid solution

1787. Neutral solution is one which has pH value__________________?
0

A. greater than 7

B. pH value has nothing to do with neutral solution

C. equal to 7

D. none of the above

E. less than 7

1788. A reversible change in the atomic structure of steel with corresponding change in the properties is known as___________________?
0

A. atomic change

B. physical change

C. solidus change

D. molecular change

E. allotropic change

1789. Capillary action is due to the_________________?
0

A. cohesion of the liquid

B. adhesion of the liquid molecules and the molecules on the surface of a solid

C. none of the above

D. all of the above

E. surface tension

1790. A liquid would wet the solid, if adhesion forces as compared to cohesion forces are________________?
0

A. more

B. less at low temperature and more at high temperature

C. there is no such criterion

D. less

E. equal

1791. Weld decay is the phenomenon found with _________________?
0

A. cast iron

B. wrought iron

C. non-ferrous materials

D. stainless steel

E. mild steel

1792. Railway rails are normally made of_______________?
0

A. mild steel

B. tungsten steel

C. cast iron steel

D. high carbon

E. alloy steel

1793. An ideal flow of any fluid must fulfill the following____________________?
0

A. Newtons law of viscosity

B. Newtons law of motion

C. Boundary layer theory

D. Continuity equation

E. Pascal law

1794. A fluid in equilibrium cant sustain____________________?
0

A. shear stress

B. compressive stress

C. tensile stress

D. bending stress

E. all of the above

1795. Argentite is the principal ore or raw material for _________________?
0

A. zinc

B. lead

C. tin

D. aluminium

E. silver

1796. A perfect gas____________________?
0

A. has zero viscosity

B. none of the above

C. has constant viscosity

D. is of theoretical interest

E. is in compressible

1797. Free cutting steels_____________________?
0

A. require least cutting force

B. contain carbon in free form

C. are used where ease in machining is the criterion

D. can be cut freely even under adverse conditions

E. do not exist

1798. Constantant an alloy used in thermocouples is an alloy of __________________?
0

A. copper and tin

B. copper and nickel

C. copper and chromium

D. copper and zinc

E. copper and iron

1799. Which of the following instruments is used to measure flow on the application of Bernoullis theorem_________________?
0

A. nozzle

B. Venturimeter

C. all of the above

D. pitot tube

E. Orifice plate

1800. Hardness of martensite is about___________________?
0

A. RC 32

B. RC 80

C. RC 65

D. RC 48

E. RC 57

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