MECHANICAL ENGINEERING MCQs

1) A flat surface can be produced by a lathe machine, if the cutting tool moves _____
a. parallel to the axis of rotation of workpiece
b. perpendicular to the axis of rotation of workpiece
c. at an angle of 450
d. none of the above
ANSWER: perpendicular to the axis of rotation of workpiece


2) What is the function of cone pulley drive in lathe machines?
a. Drive the lead screw
b. Change the spindle speed
c. Drive the tail-stock
d. All of the above
ANSWER: Change the spindle speed


3) Which of the following is a mechanism for mechanized movements of the carriage along
longitudinal axis?
a. Cross-slide
b. Compound rest
c. Apron
d. Saddle
ANSWER: Apron


4) The function of taper turning process is to ____
a. reduce the diameter of a workpiece along its length
b. reduce the diameter by removing material about an axis offset from the axis of workpiece
c. remove the material from end surface of a workpiece
d. all of the above
ANSWER: reduce the diameter of a workpiece along its length


5) The process of bevelling sharp ends of a workpiece is called as ________
a. knurling
b. grooving
c. facing
d. chamfering
ANSWER: chamfering


6) In an isolated system, ________ can be transferred between the system and its
surrounding.
a. only energy
b. only mass
c. both energy and mass
d. neither energy nor mass
ANSWER: neither energy nor mass


7) Which of the following is an extensive property?
a. Volume
b. Pressure.

c. Viscosity
d. All of the above
ANSWER: Volume


8) How is absolute pressure measured?
a. Gauge pressure + Atmospheric pressure
b. Gauge pressure – Atmospheric pressure
c. Gauge pressure / Atmospheric pressure
d. None of the above
ANSWER: Gauge pressure + Atmospheric pressure


9) The extensive properties of a system, _______
a. are independent of the mass of the system
b. depend upon temperature of the system
c. depend upon the mass of the system
d. none of the above
ANSWER: depend upon the mass of the system


10) An isobaric process, has constant _____
a. density
b. pressure
c. temperature
d. volume
ANSWER: pressure


 

11) Which of the following energy conversion devices convert heat into work?
a. Electrical generators
b. I. C engines
c. Condensers
d. All of the above
ANSWER: I. C engines


12) Lancashire boilers are ______
a. externally fired boilers
b. internally fired boilers
c. both a. and b.
d. none of the above
ANSWER: internally fired boilers


13) Smoke tube boilers have large water to steam ratio, hence _____
a. have high evaporation rates
b. are slow in operations
c. temperature stresses inducing failure of feed water arrangement are maximum
d. all of the above
ANSWER: are slow in operations


14) Which of the following statements are false for reaction turbines?
1. Flow of water can be regulated without any losses
2. It works on the principle of impulse and reaction

3. They are suitable for low heads
4. Water flows at constant atmospheric pressure over the runner
a. 1, 2 and 3
b. 2 and 4
c. 1 and 4
d. 1, 2, 3 and 4
ANSWER: 1 and 4


15) In four stroke cycle engine, cycle is completed in ______
a. two strokes of the piston
b. two revolutions of the crankshaft
c. three strokes of the piston
d. four revolutions of the crankshaft
ANSWER: two revolutions of the crankshaft


16) Which type of bearings are known as anti friction bearings?
a. Sliding contact bearings
b. Rolling contact bearings
c. Both a. and b.
d. None of the above
ANSWER: Rolling contact bearings


17) In roller bearings which type of rolling elements are used
a. Cylindrical rollers
b. Taper rollers

c. Spherical rollers
d. All of the above
ANSWER: All of the above


18) Why is the load carrying capacity low in ball bearings?
1. Due to line contact between inner race and the ball
2. Due to greater axial dimensions
3. Due to less radial dimensions
4. Due to point contact between inner race and the ball
a. 1 and 3
b. only 1
c. only 4
d. 2 and 4
ANSWER: only 4


19) Cylindrical roller bearings have greater _____
a. axial load carrying capacity
b. thrust load carrying capacity
c. radial load carrying capacity
d. all of the above
ANSWER: radial load carrying capacity


20) Which of the following statements is/are true?
a. Jaw clutch is a positive clutch
b. The power transmitting capacity of a friction clutch is inversely proportional to the coefficient
of friction between contacting surfaces

c. Driving and driven plates in friction clutches are held together due to radial force applied by
the helical springs
d. All of the above
ANSWER: Jaw clutch is a positive clutch


21) Determine torque transmitted on the pinion shaft if torque transmitted on gear shaft
is 20 Nm.
Consider Gear ratio = 4
a. 8 Nm
b. 5 Nm
c. 80 Nm
d. 16 Nm
ANSWER: 5 Nm


22) Which of the following statements is/are true for gear drives?
a. They can be used for long centre distances
b. They are used to transmit power between non-intersecting and parallel shafts
c. They cannot be used for high reduction ratios
d. All of the above
ANSWER: They are used to transmit power between non-intersecting and parallel shafts


23) In which power transmitting drive polygon effect is observed?
a. Belt drive
b. Chain drive
c. Both a. and b.
d. None of the above

ANSWER: Chain drive


24) What is meant by gear ratio?
a. The ratio of pinion speed and gear speed
b. The ratio of number of teeth on pinion and number of teeth on gear
c. Both a. and b.
d. None of the above
ANSWER: The ratio of pinion speed and gear speed


25) Which gears are used to connect two intersecting shaft axes?
a. Crossed helical gear
b. Worm and worm wheel
c. Bevel gears
d. All of the above
ANSWER: Bevel gears


26) In stress-strain diagram, up to proportional limit ______
a. stress is inversely proportional to strain
b. force is directly proportional to displacement
c. stress is directly proportional to strain
d. strain is directly proportional to stress
ANSWER: stress is directly proportional to strain


27) Deformation per unit length is called as ________
a. strain
b. stress
c. modulus of elasticity
d. none of the above
ANSWER: strain


28) Which of the following materials do not have a well defined yield point?
a. Heat treated steel
b. Concrete
c. Carbon fiber
d. All of the above
ANSWER: All of the above


29) Factor of safety is the ratio of _________
a. working stress and ultimate strength
b. yield strength and endurance strength
c. ultimate strength and yield strength
d. yield strength and working stress
ANSWER: yield strength and working stress


30) One ton of refrigeration is equal to ______
a. 120 B Th U/hr
b. 200 B Th U/hr
c. 1200 B Th U/hr
d. 12000 B Th U/hr
ANSWER: 12000 B Th U/hr


31) Which of the following statements is/are true for alloy steels?
a. They contain carbon more than 1.7%
b. They are ductile
c. They have low resilience and toughness
d. All of the above
ANSWER: They are ductile


32) Which of the following is a ferrous alloy?
a. Brass
b. Aluminum alloys
c. Cast steel
d. All of the above
ANSWER: Cast steel


33) Copper when alloyed with zinc is known as
a. Brass
b. Bronze
c. Babbits
d. All of the above
ANSWER: Brass


34) The plastic materials which do not undergo chemical change when heated are ____
a. Thermoplasts
b. Thermosets
c. Both a. and b.
d. None of the above
ANSWER: Thermoplasts


35) Which of the following is a characteristic of Polytetra-flouro-ethylene?
a. High coefficient of friction
b. Tough at high temperature
c. Resistance to chemical attack
d. All of the above
ANSWER: Resistance to chemical attack


36) Which of the following statements is/are true for mechanisms?
a. A slider crank mechanism is formed, if one link in slider crank chain is fixed
b. Three kinematic links joined together forms a mechanism
c. Kinematic chain is a part of kinematic pair
d. All of the above
ANSWER: A slider crank mechanism is formed, if one link in slider crank chain is fixed


37) Which body transmits force with negligible deformation?
a. Elastic body
b. Resistant body

c. Deforming body
d. All of the above
ANSWER: Resistant body


38) What is the primary function of mechanism?
a. Power transmission
b. Power absorption
c. Force transmission
d. Motion transmission
ANSWER: Motion transmission


39) Which of the following is an inversion of four bar chain?
a. Coupled wheels of locomotive
b. Whitworth quick return mechanism
c. Reciprocating air compressor
d. Hand pump
ANSWER: Coupled wheels of locomotive


40) What are the number of sliding and turning pairs in a slider crank mechanism?
a. 1 sliding pair and 3 turning pairs
b. 2 sliding pairs and 2 turning pairs
c. 3 sliding pairs and 1 turning pair
d. None of the above
ANSWER: 1 sliding pair and 3 turning pairs


41) What is meant by drag in casting process?
a. Upper part of casting flask
b. Molten metal
c. Lower part of casting flask
d. Upper and lower part of casting flask
ANSWER: Lower part of casting flask


42) Casting replica used to make the cavity is called as
a. Mould
b. Pattern
c. Cope
d. None of the above
ANSWER: Pattern


43) The process of joining similar or dissimilar materials by heating them below 450o C
using non-ferrous filler material is called as _____
a. Brazing
b. Soldering
c. Welding
d. All of the above
ANSWER: Soldering


44) At forging temperature when a compressive force is applied on the material, it
deforms
a. elastically in the direction of least resistance
b. elastically in the direction of maximum resistance
c. plastically in the direction of least resistance
d. plastically in the direction of maximum resistance
ANSWER: plastically in the direction of least resistance


45) What is the average temperature required for hot forging of aluminium alloys?
a. 1100 oC to 1200 oC
b. 350 oC to 525 oC
c. 2000 oC to 2500 oC
d. None of the above
ANSWER: 350 oC to 525 oC


46) Which process squeezes metals into peaks and troughs with plastic deformation?
a. Grooving
b. Knurling
c. Reaming
d. None of the above
ANSWER: Knurling


47) Which of the following operations is/are performed on a lathe machine?
a. Spot-facing
b. Parting

c. Reaming
d. All of the above
ANSWER: Parting


48) The process of chamfering the entrance of a drilled hole is known as_____
a. counter-boring
b. counter-sinking
c. counter-fillet
d. trepanning
ANSWER: counter-sinking


49) On drilling machine, which process is known as reaming?
a. Enlargement of existing hole
b. Hole made by removal of metal along the hole circumference
c. Smoothly finishing and accurately sizing a drilled hole
d. All of the above
ANSWER: Smoothly finishing and accurately sizing a drilled hole


50) Which of the following statements is/are false for machine tools?
1. Pillar drilling machine drills holes up to 75 mm
2. Regulating wheel is a component of surface grinding machine
3. Sensitive drilling machine is also known as bench drilling machine
4. The chuck of an internal grinding machine placed in tailstock is driven by an electric
motor
a. Only 1
b. 2 and 4

c. 1 and 3
d. All of the above
ANSWER: 2 and 4


51) The radiation pyrometers work on the principle of ______
a. Newton’s law
b. Stefan Boltzmann’s law
c. Zeroth law
d. None of the above
ANSWER: Stefan Boltzmann’s law


52) Which of the following relations depict relation between Celsius and Fahrenheit scale?
a. (oC / 5) = (oF – 32) / 9
b. (oC / 9) = (oF – 32) / 5
c. (oC / 32) = (oF – 9) / 5
d. None of the above
ANSWER: (oC / 5) = (oF – 32) / 9


53) According to Joule’s law, the internal energy of a perfect gas is the function of
absolute ______
a. density
b. pressure
c. temperature
d. volume

ANSWER: temperature


54) According to Kelvin-Planck statement, it is impossible to construct a device operating
on a cycle which transfers heat from ____
a. low pressure heat reservoir to high pressure reservoir
b. low temperature heat reservoir to high temperature reservoir
c. high pressure heat reservoir to low pressure reservoir
d. high temperature heat reservoir to low temperature reservoir
ANSWER: low temperature heat reservoir to high temperature reservoir


55) Which of the following relations is true, for coefficient of performance (C.O.P)?
a. (C.O.P)heat pump – (C.O.P)refrigerator = 1
b. (C.O.P)heat pump – (C.O.P)refrigerator > 1
c. (C.O.P)heat pump – (C.O.P)refrigerator < 1
d. (C.O.P)heat pump – ( C.O.P)refrigerator = 0
ANSWER: (C.O.P)heat pump – (C.O.P)refrigerator = 1


56) Thermal efficiency of S.I. engines is low, due to ____
a. low compression ratio
b. high compression ratio
c medium compression ratio
d. none
ANSWER: low compression ratio


57) Pump transfers input mechanical energy of an engine, into ______
a. pressure energy of a fluid
b. kinetic energy of a fluid
c. both a. and b.
d. none of the above
ANSWER: both a. and b.


58) Which of the following protects penstock due to sudden variation of flow or velocity of  water?
a. Anchors
b. Forebays
c. Trash rack
d. Surge tank
ANSWER: Surge tank