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This set of Machine Design Multiple Choice Questions & Answers (MCQs) focuses on Machine Design Set 2
Q1 | In a horizontal flat belt drive for power transmission it is customary to use
- bottom side of the belt as slack side
- top side of the belt as slack side
- crossed-belting
- none of the above
- Cast steel
Q2 | Auto frettage is a
- extra cover provided on seamless pipes to increase their hoop stress
- a means of inducing favourable residual stresses in pressure vessels
- Increasing the diameter of threaded portion
- a heat treatment for pressure vessels subjected to low temperatures
- surface coating process
Q3 | Bush bearings
- Phosphor bronze
- Aluminium bronze
- Mild steel
- White metal alloys
- None of the above
Q4 | In a standard coarse thread bolt the stress concentration is maximum at
- Top surface
- Pitch circle
- Root
- All over the surface
- Flank
Q5 | In case of worm and worm-wheel the maximum efficiency is obtained when
- Worm is driver
- Worm wheel is driver
- Either of the worm or worm wheel is a driver
- Depends on other factors
- None of the above
Q6 | When properly made, a butt weld has the strength equal to
- Double the tensile strength of plates
- Half the tensile strength of plates
- Half the compressive strength of plates
- The strength of the welded plates
- Double the compressive strength of plates
Q7 | In case of steels, as the percentage of carbon content increases
- Percentage elongation decreases
- Weldability increases
- Tensile strength decreases
- Hardness decreases
- Tapered bearing
Q8 | At the first critical speed a shaft will
- Remain straight
- Bend to the simplest shape possible
- Bend to maximum permissible depth
- Bend to the convex form
- Vibrate producing audible sound
Q9 | In order to reverse the direction of rotation of a 3-phase induction motor
- Motor should eb replaced
- Power factor should be changed
- Supply voltage should be cut off in one phase
- Any two phases should be interchanged
- All the three phases should be interchanged
Q10 | The basic hole is one which has
- Upper deviation as zero
- Lower deviation as zero
- Lower as well as upper deviation within narrow limits
- Lower as well as upper deviation are zero
- None of the above
Q11 | In a Vee belt the angle between the sides is
- 30?
- 20?
- 60?
- 40?
- 10?
Q12 | Gerber line for failure criteria is in the form of a
- parabola
- Increasing the diameter of threaded portion
- straight line with negative slope
- straight line with positive slope
- hyperbola
Q13 | Which of the following formula for columns takes into account any initial crookedness of the column and imperfectness of axial loading?
- Secant formula
- Increasing the diameter of threaded portion
- Euler's formula
- Rankiness formula
- Perry Robertson formula
Q14 | While designing a shaft pulley and key for a system
- Shaft is the weakest member
- Pulley is the weakest member
- Key is the weakest member
- All are designed for equal strength
- None of the above
Q15 | In case of biaxial stress system when a member is subjected to tensile stresses in two perpendicular directions the maximum shear stress in case of mild steel occurs on a plane inclined at
- 22
- 75?
- 45?
- 67
- 30?
Q16 | For a bearing which of the following is maximum?
- Minimum life
- Average life
- Median life
- (A), (B) and (C) above are identical
- Increasing the diameter of threaded portion
Q17 | The approximate value of allowable stress for carbon steel under static loading (in kg/cm2) is
- 500-1000
- 10000-15000
- 4000-7500
- 20000-25000
- 15000-20000
Q18 | Stub tooth is
- Longer than standard tooth depth
- Non-standard tooth
- Shorter than standard tooth depth
- Equivalent rack tooth
- Standard gear tooth
Q19 | Self-tapping screws are generally used in
- Shear metal work
- Machine tools
- Automobiles
- Aeroplanes
- None of the above
Q20 | Fatigue is mostly initiated at
- core
- centre
- Increasing the diameter of threaded portion
- surface
- core
Q21 | Which of the following joint is used for pipes carrying water under low pressures?
- Socket joint
- Increasing the diameter of threaded portion
- Expansion joint
- Adhesive joint
- Welded joint
Q22 | In case of steels, as the percentage of carbon content increases
- Elongation increases
- Chrome steel
- Hardness decreases
- Tensile strength increases
- Weldability increases
Q23 | If screw threads are to be used in a situation involving high stresses in one direction only, the types of threads suitable for this would be
- BA
- BSW
- Buttress
- Acme
- Square
Q24 | A solderberg line for ductile material gives upper limit for
- Increasing the diameter of threaded portion
- alternating tensile stress
- alternating compressive stress
- any combination of mean and alternating stresses
- mean stress
Q25 | If water in closed pipe freezes, the pipe will
- Rupture in a plane inclined at 45 degree to the longitudinal axis of the pipe
- Rupture along a line running longitudinally along the pipe
- Rupture along a plane perpendicular to the axis of pipe
- Rupture zig-zag along the length
- Rupture along weakest circumferential section