Recently Updated Designing Engineer Objective Questions
Q – 1 Which of the following screw thread is used for power transmission in one direction only.
A. Acme threads
B. Square threads
C. Buttress threads
D. Multiple threads
Ans- Option C
Q – 2 The resistance to fatigue of a material is measured by
A. elastic limit
B. Young’s modulus
C. ultimate tensile strength
D. endurance limit
Ans- Option D
Q – 3 The pipe joint mostly used for pipes carrying water at low pressures is
A. socket joint
B. nipple joint
C. union joint
D. spigot and socket joint
Ans- Option A
Q – 4 When a nut is tightened by placing a washer below it, the bolt will be subjected to
A. tensile stress
B. compressive stress
C. shear stress
D. none of these
Ans- Option A
Q – 5 In unilateral system of tolerance, the tolerance is allowed on
A. one side of the actual size
B. one side of the nominal size
C. both sides of the actual size
D. both sides of the nominal size
Ans- Option B
Q – 6 The material used for brake lining should have __________ coefficient of friction.
A. low
B. high
Ans- Option B
Q – 7 A column is known as a long column if the slenderness ratio is
A. 40
B. 50
C. 70
D. 100
Ans- Option D
Q – 8 In an ordinary bolt, the effect of the impulsive loads applied axially is concentrated on the cross-sectional area at the root of the threads.
A. Yes
B. No
Ans- Option A
Q – 9 When the bearing is subjected to large fluctuations of load and heavy impacts, the bearing characteristic number should be __________ the bearing modulus.
A. 5 times
B. 10 times
C. 15 times
D. 20 times
Ans- Option C
Q – 10 Circumferential joint in boilers is used to get the required length of a boiler.
A. True
B. False
Ans- Option A
Q – 11 A locking device extensively used in marine type connecting rod ends is a
A. jam nut
B. castle nut
C. sawn nut
D. ring nut
Ans- Option D
Q – 12 Soderberg relation is based on __________ of the material whereas all other failure relation for dynamic loading are based on ultimate strength of the material.
A. elastic strength
B. yield strength
C. shear strength
Ans- Option B
Q – 13 A transmission shaft includes
A. counter shaft
B. line shaft
C. over head shaft
D. all of these
Ans- Option D
Q – 14 A steel containing more than 0.8% carbon is known as eutectoid steel.
A. Yes
B. No
Ans- Option B
Q – 15 The radial distance of a tooth from the pitch circle to the top of the tooth is called
A. dedendum
B. addendum
C. clearance
D. working depth
Ans- Option B
Q – 16 The difference between the tooth space and the tooth thickness as measured on the pitch circle, is called
A. working depth
B. clearance
C. face width
D. backlash
Ans- Option D
Q – 17 The load cup of a screw jack is made separate from the head of the spindle to
A. enhance the load carrying capacity of the jack
B. reduce the effort needed for lifting the working load
C. prevent the rotation of load being lifted
D. reduce the value of frictional torque
Ans- Option C
Q – 18 A screw is said to be over hauling screw, if its efficiency is
A. less than 50%
B. more than 50%
C. equal to 50%
D. none of these
Ans- Option B
Q – 19 When screw threads are to be used in a situation where power is being transmitted in one direction only, then the screw threads suitable for this will be
A. square threads
B. acme threads
C. knuckle threads
D. buttress threads
Ans- Option D
Q – 20 A sliding bearing which operates without any lubricant present, is called
A. zero film bearing
B. boundary lubricated bearing
C. hydrodynamic lubricated bearing
D. hydrostatic lubricated bearing
Ans- Option A
Q – 21 The backlash for spur gears depends upon
A. module
B. pitch line velocity
C. tooth profile
D. both (a) and (b)
Ans- Option D
Q – 22 In second type of levers,
A. load is in between the fulcrum and effort
B. effort is in between the fulcrum and load
C. fulcrum is in between the load and effort
D. none of these
Ans- Option A
Q – 23 The square threads are not so strong as V-threads but they offer less frictional resistance to motion than Whitworth threads.
A. Correct
B. Incorrect
Ans- Option A
Q – 24 In a gear, having involute teeth, the normal to the involute is a tangent to the
A. pitch circle
B. base circle
C. addendum circle
D. dedendum circle
Ans- Option B
Q – 25 Screws jacks have multiple threads.
A. Agree
B. Disagree
Ans- Option B
Q – 26 When two non-intersecting and non-coplaner shafts are connected by gears, the arrangement is known as
A. spur gearing
B. helical gearing
C. bevel gearing
D. spiral gearing
Ans- Option D
Q – 27 The size of a gear is usually specified by
A. pressure angle
B. pitch circle diameter
C. circular pitch
D. diametral pitch
Ans- Option B
Q – 28 An open belt drive is used when
A. shafts are arranged parallel and rotate in the opposite directions
B. shafts are arranged parallel and rotate in the same directions
C. shafts are arranged at right angles and rotate in one definite direction
D. driven shaft is to be started or stopped whenever desired without interferring with the driving shaft
Ans- Option B
Q – 29 The number of slots in a 25 mm castle nut is
A. 2
B. 4
C. 6
D. 8
Ans- Option C
Q – 30 For unequal width of butt straps, the thickness of butt straps are
A. 0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside
B. 0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside
C. 0.75 t for both the straps on the inside and outside
D. 0.625 t for both the straps on the inside and outside
Ans- Option A
Q – 31 Which of the following material has the maximum ductility?
A. Mild steel
B. Copper
C. Zinc
D. Aluminium
Ans- Option A
Q – 32 The rolling contact bearings are known as
A. thick lubricated bearings
B. plastic bearings
C. thin lubricated bearings
D. antifriction bearings
Ans- Option D
Q – 33 Which of the following statement is correct?
A. The toughness of a material increases when it is heated.
B. The shear stress in a beam varies from zero at the neutral surface and maximum at the outer fibres.
C. The stress concentration in static loading is more serious in brittle materials and less serious in ductile materials.
D. The stress concentration in static loading is more serious in ductile materials and less serious in brittle materials.
Ans- Option C
Q – 34 When a load W is suddenly applied to a bar of weight W1, the stress induced in the bar will increase with the increase in weight W1.
A. Correct
B. Incorrect
Ans- Option B
Q – 35 The taper on cotter varies from
A. 1 in l5 to 1 in 10
B. 1 in 24 to 1 in 20
C. 1 in 32 to 1 in 24
D. 1 in 48 to 1 in 24
Ans- Option D
Q – 36 In a hydrodynamic lubricated bearing
A. there is a thick film of lubricant between the journal and the bearing
B. there is a thin film of lubricant between the journal and the bearing
C. there is no lubricant between the journal and the bearing
D. the lubricant is forced between the journal and the bearing, by external pressure
Ans- Option A
Q – 37 In radial cams, the follower moves
A. in a direction perpendicular to the cam axis
B. in a direction parallel to the cam axis
C. in any direction irrespective of cam axis
D. along the cam axis
Ans- Option A
Q – 38 In a flange coupling, the flanges are coupled together by means of
A. bolts and nuts
B. studs
C. headless taper bolts
D. none of these
Ans- Option A
Q – 39 The toughness of a material __________ when it is heated.
A. increases
B. decreases
C. does not change
Ans- Option B
Q – 40 Surface endurance limit of gear material is dependent upon its
A. elastic strength
B. yield strength
C. brinell hardness number
D. toughness
Ans- Option C
Q – 41 In leaf springs, the longest leaf is known as
A. lower leaf
B. master leaf
C. upper leaf
D. none of these
Ans- Option B
Q – 42 Stress concentration is caused due to
A. variations in load acting on a member
B. variations in properties of materials in a member
C. abrupt change of cross-section
D. all of these
Ans- Option C
Q – 43 When a bolt is subjected to shock loading, the resilience of the bolt should be considered in order to prevent breakage at the
A. head
B. shank
C. thread
D. middle
Ans- Option C
Q – 44 According to Indian standard specifications, 100 H6/g5 means that the
A. actual size is 100 mm
B. basic size is 100 mm
C. difference between the actual size and basic size is 100 mm
D. none of the above
Ans- Option B
Q – 45 A crankshaft is a __________ shaft.
A. transmission
B. machine
Ans- Option B
Q – 46 The application of third type levers is found in
A. handle of a hand pump
B. hand wheel of a punching press
C. lever of a loaded safety valve
D. a pair of tongs
Ans- Option D
Q – 47 A locking device in which the bottom cylindrical portion is recessed to receive the tip of the locking set screw, is called
A. castle nut
B. jam nut
C. ring nut
D. sawn nut
Ans- Option C
Q – 48 The velocity of sliding __________ the distance of the point of contact from the pitch point.
A. is directly proportional to
B. is inversely proportional to
C. is equal to cos φ multiplied by
D. does not depend upon
Ans- Option A
Q – 49 The ball bearings are provided with a cage
A. to reduce friction
B. to facilitate slipping of balls
C. to prevent the lubricant from flowing out
D. to maintain the balls at a fixed distance apart
Ans- Option D
Q – 50 The value of stress concentration factor depends upon
A. material of the part
B. geometry of the part
C. material and geometry of the part
D. none of these
Ans- Option C
Q – 51 In order to obtain the bolts of uniform strength, an axial hole is drilled through the head as far as the threaded portion such that the area of shank becomes equal to the root area of the thread.
A. True
B. False
Ans- Option A
Q – 52 The constant factor in case of R10 series of preferred numbers is
A. 1.06
B. 1.12
C. 1.26
D. 1.58
Ans- Option C
Q – 53 Which of the following statement is correct for gears?
A. The addendum is less than dedendum
B. The pitch circle diameter is equal to the product of module and number of teeth
C. The pitch circle is always greater than the base circle
D. all of the above
Ans- Option D
Q – 54 Two shafts A and B under pure torsion are of identical length and identical weight and are made of the same material. The shaft A is solid and the shaft B is hollow. We can say that
A. shaft B is better than shaft A
B. shaft A is better than shaft B
C. both the shafts are equally good
Ans- Option A
Q – 55 The bearings of heavy series have capacity __________ over the medium series.
A. 10 to 20%
B. 20 to 30%
C. 30 to 40%
D. 40 to 50%
Ans- Option B
Q – 56 The maximum normal stress theory is used for
A. brittle materials
B. ductile materials
C. plastic materials
D. non-ferrous materials
Ans- Option A
Q – 57 The endurance limit for a mirror polished material will be __________ as compared to unpolished material.
A. same
B. less
C. more
Ans- Option C
Q – 58 The rolling contact bearings as compared to sliding contact bearings have
A. small overall dimensions
B. accuracy of shaft alignment
C. low starting and low running friction except at very high speeds
D. all of the above
Ans- Option D
Q – 59 In a flange coupling, the thickness of flanges is taken as one-half the diameter of shaft.
A. Agree
B. Disagree
Ans- Option A
Q – 60 According to Guest’s theory, the failure occurs at a point in a member when the maximum shear stress in a bi-axial stress system reaches the shear stress at elastic limit in simple tension test.
A. True
B. False
Ans- Option A
Q – 61 In order to avoid tearing of the plate at an edge, the distance from the centre line of the rivet hole to the nearest edge of the plate should be equal to (where d = Diameter of rivet hole)
A. d
B. 1.5 d
C. 2 d
D. 2.5 d
Ans- Option B
Q – 62 Slenderness ratio is the ratio of
A. maximum size of column to minimum size of column
B. width of column to depth of column
C. effective length of column to least radius of gyration of the column
D. effective length of column to width of column
Ans- Option C
Q – 63 Which of the following statement is wrong ?
A. The power transmitted by V-belts is less than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts
B. The V-belt drive is used with large centre distance
C. The V-belt may be operated in either direction with tight side of the belt at the top or bottom
D. The ratio of driving tensions in V-belt drive is more than flat belt drives
Ans- Option B
Q – 64 A sliding bearing in which the working surfaces are completely separated from each other by lubricant is called zero film bearing.
A. True B. False
Ans- Option B
Q – 65 The number of rivets in shear shall be equal to the number of rivets in crushing.
A. Correct B. Incorrect
Ans- Option A
Q – 66 Screws used for power transmission should have
A. Low efficiency
B. high efficiency
C. very fine threads
D. strong teeth
Ans- Option B
Q – 67 When bevel gears connect two shafts whose axes intersect at an angle greater than a right angle and one of the bevel gears has a pitch angle of 90°, then they are known as
A. angular bevel gears
B. crown bevel gears
C. internal bevel gears
D. mitre gears
Ans- Option B
Q – 68 The sleeve or muff coupling is designed as a
A. dun cylinder
B. thick cylinder
C. solid shaft
D. hollow shaft
Ans- D. hollow shaft