Description : Efficiency of screw depends upon lead of the screw. a) True b) False
Last Answer : a) True
Description : Efficiency of the screw _______ with increase of coefficient of friction. a) decreases b) increases c) has no effect d) cannot be determined
Last Answer : a) decreases
Description : Self-locking takes place when a) Coefficient of friction is equal to or greater than the tangent of the helix angle b) Coefficient of friction is lesser than or equal to the tangent of the helix ... friction is equal to or greater than the tangent of the helix angle d) None of the mentioned
Last Answer : c) Coefficient of friction is equal to or greater than the tangent of the helix angle
Description : Efficiency of a screw jack in maximum when its 31 helix angle, ? is a.45 + ?/2 b.107 dynes c.? d.45 - ?/2 e.45?
Last Answer : d. 45 - ?/2
Description : Consider tile following statements: [IES-1993; 2002; 2006] Radius of friction circle for a journal bearing depends upon 1. Coefficient of friction 2. Radius of the journal 3. Angular speed of rotation of the shaft Which of the ... ) 1,2 and 3 (b) Only 1 and 2 (c) Only 2 and 3 (d) Only 1 and 3
Last Answer : (b) Only 1 and 2
Description : Jam nut is a locking device in which (A) A smaller nut is tightened against main nut creating friction at the contacting surface (B) A split pin is passed through diametrically opposite slots in nut and ... parts of nut separated by slot (D) An elastic piece is tightened in the nut by a setscrew
Last Answer : (A) A smaller nut is tightened against main nut creating friction at the contacting surface
Description : Castle nut is a locking device in which (A) A smaller nut is tightened against main nut creating friction at the contacting surface (B) A split pin is passed through diametrically opposite slots in nut and ... of nut separated by slot (D) An elastic piece is tightened in the nut by a setscrew
Last Answer : (B) A split pin is passed through diametrically opposite slots in nut and a hole in bolt and the two ends of split pin are separated and bent back on nut
Description : Nominal diameter of the screw thread is the same as core diameter. a) True b) False
Last Answer : b) False
Description : In manual assembly, cost of screw is higher than the cost of driving a screw. a) True b) False
Description : Maximum possible efficiency of a self-locking screw is a) 50% b) 75% c) 66% d) 33%
Last Answer : a) 50%
Description : Threads used in screw fasteners are ______ a. having high strength b. having low efficiency c. single start type d. all of the above
Last Answer : d. all of the above
Description : The maximum efficiency of a square threaded screw is (A) (1 - sinφ)/ (1 + sinφ) (B) (1 + sinφ)/ (1 - sinφ)s (C) (1 - sinφ)/ (1 + cosφ) (D) (1 + cosφ)/ (1 - sinφ)
Last Answer : (A) (1 - sinφ)/ (1 + sinφ)
Description : The helix angle in case of closely coiled helical spring is (A) less than 5° (B) 5° to 7° (C) 7° to 10° (D) more than 10°
Last Answer : (D) more than 10°
Description : The helix angle in case of closely coiled helical spring is (A) less than 10° (B) 10° to 15° (C) 15° to 20° (D) more than 20°
Last Answer : (A) less than 10°
Description : The helix angle is very small about 20. The spring is open coiled spring. a) Yes b) It is closed coiled spring c) That small angle isn’t possible d) None of the listed
Last Answer : b) It is closed coiled spring
Description : Coarse threads have helix angle _____ fine threads. a) Equal to b) Greater than c) Lesser than d) There is no relation
Last Answer : c) Lesser than
Description : The helix angle for double helical gears may be made up to (A) 45° (B) 60° (C) 75° (D) 90°
Last Answer : (A) 45°
Description : The ideal angle of banking provided on roads a.Depends on (velocity)2 of vehicle b.Depends on the nature of road surface c.Depend on coefficient of friction between the road and the vehicle cantact point d.Depends on weight of the vehicle e.All above
Last Answer : a. Depends on (velocity)2 of vehicle
Description : Assertion (A): Oil as a cutting fluid result in a lower coefficient of friction. Reason (R): Oil forms a thin liquid film between the tool face and chip, and it provides 'hydrodynamic lubrication'. [IES- 2000] (a ... explanation of A (c) A is true but R is false (d) A is false but R is true
Last Answer : (c) A is true but R is false
Description : Assertion (A): In anti-friction bearings, the frictional resistance is very low as the shaft held by it remains in floating condition by the hydrodynamic pressure developed by the lubricant. [IES-2006] Reason (R): In hydrodynamic ... of A (c) A is true but R is false (d) A is false but R is true
Last Answer : (d) A is false but R is true
Description : The efficiency of a dual combustion cycle __________ upon cut-off ratio. A. depends B. does not depend
Last Answer : Answer: A
Description : Entire torque is transmitted by friction in the clamp coupling. a) True b) False
Description : Saddle key is transmit power or torque through friction resistant only A. True B. False
Last Answer : A. True
Description : Assertion A.: The determination of pH value of sewerage is important. Reason (R): The efficiency of certain treatment methods depends upon the availability of pH value. A. Both A and R are true and R is the ... correct explanation of A C. A is true but R is false D. A is false but R is true
Last Answer : ANS: A
Description : The resultant axial force on bolt depends upon (A) Initial tension (B) External applied load (C) Stiffness of bolt and parts held by bolt (D) All three factors
Last Answer : (D) All three factors
Description : A concentric spring consist of two helical compression springs (A) both springs always have right hand helix (B) both springs always have left hand helix (C) both springs always have opposite hand of helices (D) any of the above
Last Answer : (C) both springs always have opposite hand of helices
Description : The friction factor for turbulent flow in a hydraulically smooth pipe (A) Depends only on Reynolds number (B) Does not depend on Reynolds number (C) Depends on the roughness (D) None of these
Last Answer : (A) Depends only on Reynolds number
Description : Friction factor for fluid flow in pipe does not depend upon the (A) Pipe length (B) Pipe roughness (C) Fluid density & viscosity (D) Mass flow rate of fluid
Last Answer : A) Pipe length
Description : If the lateral force acting on the set screw is large and tends to displace one part with respect to other than which point is recommended? a) Dog Point b) Cone Point c) Window Point d) Cut Point
Last Answer : a) Dog Point
Description : If a fastener is threaded into a tapped hole, then the fastener is likely to be called as a) Screw b) Bolt c) Washer d) Screw or bolt
Last Answer : a) Screw
Description : Which type of screw fasteners are threaded through out its length? a. Cap screws b. Set screws c. Studs d. Tap bolt
Last Answer : b. Set screws
Description : Allen key is used to tighten (A) Cap screw with hexagonal head (B) Cap screw with fillister head (C) Cap screw with hexagonal socket head (D) Cap screw with flat head
Last Answer : (C) Cap screw with hexagonal socket head
Description : A screw is specified by (A) Major diameter (B) Minor diameter (C) Pitch diameter (D) Mean diameter
Last Answer : (A) Major diameter
Description : The largest diameter of external or internal screw thread is called (A) Major diameter (B) Minor diameter (C) Pitch diameter (D) None of the above
Description : Setscrews are (A) Similar to tap bolts except that a greater variety of shapes of heads are available (B) Slotted for screw driver and generally used with a nut (C) Used to prevent relative motion between parts (D) Similar to studs
Last Answer : (C) Used to prevent relative motion between parts
Description : While designing screw threads, adequate length of engaged threads between the screw and nut is provided so as to prevent failure of threads due to (A) Direct shear stress (B) Torsional shear stress (C) Tensile stress (D) Compressive stress
Last Answer : (A) Direct shear stress
Description : Which of the following statements is/are true for coulomb damping? 1. Coulomb damping occurs due to friction between two lubricated surfaces2. Damping force is opposite to the direction of motion of vibrating body ... 2, 3 and statement 4 c. Only statement 2 d. All the above statements are true
Last Answer : c. Only statement 2
Description : Which of the following are not true for petroff’s equation? a) Shaft is considered concentric with the bearing b) Bearing is subjected to light load c) Is used to find coefficient of friction d) Frictional torque is given by fpr2l
Last Answer : d) Frictional torque is given by fpr2l
Description : Partial bearing is preferred over journal bearing. a) True b) No c) More friction losses d) Can’t be determined
Description : Which one of the following statements is true for Mohr-Coulomb envelope? (A) Coulomb suggests that the relationship between shear strength and normal stress, is adequately represented by the straight line ... exists among the principal stress and the angle of internal friction (D) All the above
Last Answer : Answer: Option D
Description : The efficiency of sedimentation tank does not depend upon (A) Depth of tank (B) Length of tank (C) Detention period (D) Velocity of water
Last Answer : (D) Velocity of water
Description : Consumption demand does not depend upon the level of (a) Income ; (b) Propensity to consume ; (c) Consumer spending ; (d) Marginal efficiency of investment.
Last Answer : (d) Marginal efficiency of investment.
Description : According to Water-Cement Ratio Law, the strength of workable plastic concrete (A) Depends upon the amount of water used in the mix (B) Does not depend upon the quality of cement mixed with aggregates (C) Does not depend upon the quantity of cement mixed with aggregates (D) All the above
Description : Angle of nip of the crushing rolls does not depend upon the (A) Diameter of the rolls (B) Speed of the rolls (C) Product size (D) Feed size
Last Answer : (B) Speed of the rolls
Description : Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres ( ... factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number
Last Answer : (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads
Description : In the complete turbulence zone (in rough pipes), the (A) Rough and smooth pipes have the same friction factor (B) Laminar film covers the roughness projections (C) Friction factor depends upon NRe only (D) Friction factor is independent of the relative roughness
Last Answer : (D) Friction factor is independent of the relative roughness
Description : The coefficient of friction depends upon (A) Nature of surfaces (B) Area of contact (C) Shape of the surfaces (D) All of the above
Last Answer : (A) Nature of surfaces
Description : The purpose of lubrication in an antifriction bearing is (a) to reduce the friction between balls and races (b) dissipation of frictional heat prevention of corrosion (c) protection of the bearing from dirt and other foreign particles (d) all of the mentioned
Last Answer : (d) all of the mentioned
Description : The antifriction bearings (a) have low starting and low running friction at moderate speeds (b) have a high initial cost (c) can carry both radial and thrust loads (d) all the mentioned
Last Answer : (d) all the mentioned